Update Custom Entitlements Sample app (#1166)

Adds quite a few things to the Custom Entitlements Sample app: 

- A tutorial mode that when tapped, provides an explanation for what the
mode does
- Displays the current app user ID at all times
- Moved the customer info JSON into its own view, such that the main
view shows a list of all the values that have been fired from the
listener

|  |  |  |
| :-: | :-: | :-: |
| <img width="402" alt="Screenshot 2023-07-21 at 5 54 21 PM"
src="https://github.com/RevenueCat/purchases-android/assets/3922667/18f72a28-8aee-4e2e-a6de-f56fe50c3095">
| <img width="407" alt="Screenshot 2023-07-21 at 5 54 09 PM"
src="https://github.com/RevenueCat/purchases-android/assets/3922667/d1d86378-d790-48ed-b3f9-3027553a874a">
| <img width="396" alt="Screenshot 2023-07-21 at 5 31 56 PM"
src="https://github.com/RevenueCat/purchases-android/assets/3922667/54cb9961-a568-4e44-9e1c-9eb813573a1a">
|

examples/CustomEntitlementComputationSample/app/src/main/AndroidManifest.xml

@@ -26,4 +26,4 @@
         </activity>
     </application>
 
-</manifest>
+</manifest>

examples/CustomEntitlementComputationSample/app/src/main/java/com/revenuecat/sample/CustomEntitlementComputationApp.kt

@@ -2,12 +2,12 @@ package com.revenuecat.sample
 
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.tooling.preview.Preview
-import com.revenuecat.sample.main.MainScreen
+import com.revenuecat.sample.main.MainScreenNavigation
 import com.revenuecat.sample.ui.theme.CustomEntitlementComputationTheme
 
 @Composable
 fun CustomEntitlementComputationApp() {
-    MainScreen()
+    MainScreenNavigation()
 }
 
 @Preview

examples/CustomEntitlementComputationSample/app/src/main/java/com/revenuecat/sample/main/CustomerInfoDetailScreen.kt

@@ -0,0 +1,44 @@
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun CustomerInfoDetailScreen(event: CustomerInfoEvent) {
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = {
+                    Text(text = "Customer Info Detail")
+                },
+            )
+        },
+    ) {
+        Box(modifier = Modifier.padding(it)) {
+            Column(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .background(color = Color.White),
+                horizontalAlignment = Alignment.CenterHorizontally,
+                verticalArrangement = Arrangement.Center,
+            ) {
+                Text(
+                    text = event.customerInfo.rawData.toString(4),
+                    modifier = Modifier.padding(16.dp)
+                )
+            }
+        }
+    }
+}

examples/CustomEntitlementComputationSample/app/src/main/java/com/revenuecat/sample/main/CustomerInfoEventList.kt

@@ -0,0 +1,65 @@
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.revenuecat.purchases.CustomerInfo
+import com.revenuecat.sample.ui.theme.CustomEntitlementComputationTheme
+import org.json.JSONObject
+import java.util.Date
+import java.util.UUID
+
+data class CustomerInfoEvent(
+    val date: Date = Date(),
+    val customerInfo: CustomerInfo,
+    val id: UUID = UUID.randomUUID(),
+)
+
+@Composable
+fun CustomerInfoEventsList(events: List<CustomerInfoEvent>, onEventClicked: (CustomerInfoEvent) -> Unit) {
+    LazyColumn {
+        items(events) { event ->
+            CustomerInfoEventsListItem(event = event, onEventClicked = onEventClicked)
+        }
+    }
+}
+
+@Composable
+fun CustomerInfoEventsListItem(event: CustomerInfoEvent, onEventClicked: (CustomerInfoEvent) -> Unit) {
+    Column(
+        modifier = Modifier
+            .clickable { onEventClicked(event) }
+            .padding(16.dp)
+    ) {
+        Text(
+            text = buildAnnotatedString {
+                withStyle(style = SpanStyle(fontWeight = FontWeight.Bold)) {
+                    append("Fired at: ")
+                }
+                append(event.date.toString())
+            }
+        )
+        Spacer(modifier = Modifier.height(4.dp))
+        Text(
+            text = buildAnnotatedString {
+                withStyle(style = SpanStyle(fontWeight = FontWeight.Bold)) {
+                    append("App User ID: ")
+                }
+                append(event.customerInfo.originalAppUserId)
+            }
+        )
+    }
+}

examples/CustomEntitlementComputationSample/app/src/main/java/com/revenuecat/sample/main/ExplanationScreen.kt

@@ -0,0 +1,77 @@
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.revenuecat.sample.ui.theme.CustomEntitlementComputationTheme
+
+@Composable
+fun ExplanationScreen(onDismiss: () -> Unit) {
+    Surface(color = Color.White) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(16.dp),
+            verticalArrangement = Arrangement.Center,
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            Text(
+                text = "Custom Entitlements Mode",
+                style = MaterialTheme.typography.headlineSmall,
+                modifier = Modifier.padding(8.dp)
+            )
+
+            Text(
+                text = "This mode is intended for apps that will do their own entitlement " +
+                    "computation, separate from RevenueCat.",
+                modifier = Modifier.padding(8.dp)
+            )
+
+            Text(
+                text = "In this mode, RevenueCat will not generate anonymous user IDs, " +
+                    "it will not refresh customerInfo cache automatically " +
+                    "(only when a purchase goes through), and it will disallow methods " +
+                    "other than those for configuration, switching users, " +
+                    "getting offerings and purchases.",
+                modifier = Modifier.padding(8.dp)
+            )
+
+            Text(
+                text = "Use switchUser to switch to a different App User ID if needed. " +
+                    "The SDK should only be configured once the initial appUserID is known.",
+                modifier = Modifier.padding(8.dp)
+            )
+
+            Text(
+                text = "Apps using this mode rely on webhooks to signal their backends to " +
+                    "refresh entitlements with RevenueCat.",
+                modifier = Modifier.padding(8.dp)
+            )
+
+            Spacer(modifier = Modifier.weight(1f, true))
+            Button(
+                onClick = onDismiss,
+                content = { Text("Close") }
+            )
+        }
+    }
+
+}
+
+@Preview
+@Composable
+fun ExplanationScreenPreview() {
+    CustomEntitlementComputationTheme {
+        ExplanationScreen(onDismiss = {})
+    }
+}