Make sure default variant is always used in CI end-2-end tests (#3045)

Task/Issue URL:
https://app.asana.com/0/488551667048375/1204340991927492/f

### Description
This PR makes sure the default variant is always used when running end
to end tests on CI

### Steps to test this PR

- [x] Build the app normally and a variant should be allocated to your
- [x] Build the app using `-Pforce-default-variant`, for example
`./gradlew installInternalDebug -Pforce-default-variant` and make sure
you are always assigned the default variant.
- [x] All CI tests should also pass in this PR
- [x] All tests in
https://github.com/duckduckgo/Android/actions/runs/4637681307 should
pass and if they are not is not because the onboarding cannot be
finished

.github/workflows/ads-end-to-end.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Assemble release APK
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: assembleInternalRelease
+          arguments: assembleInternalRelease -Pforce-default-variant
 
       - name: Move APK to new folder
         if: always()

.github/workflows/build-debug-apk.yaml

@@ -32,7 +32,7 @@ jobs:
       - name: Build
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: assembleInternalDebug
+          arguments: assembleInternalDebug -Pforce-default-variant
 
       - name: Obtain debug apk
         if: always()

.github/workflows/end-to-end.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Assemble release APK
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: assemblePlayRelease
+          arguments: assemblePlayRelease -Pforce-default-variant
 
       - name: Move APK to new folder
         if: always()

.github/workflows/privacy-dashboard-end-to-end.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Assemble release APK
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: assemblePlayRelease
+          arguments: assemblePlayRelease -Pforce-default-variant
 
       - name: Move APK to new folder
         if: always()

app-build-config/app-build-config-api/src/main/java/com/duckduckgo/appbuildconfig/api/AppBuildConfig.kt

@@ -31,6 +31,7 @@ interface AppBuildConfig {
     val manufacturer: String
     val model: String
     val deviceLocale: Locale
+    val isDefaultVariantForced: Boolean
 }
 
 enum class BuildFlavor {

app/build.gradle

@@ -49,6 +49,11 @@ android {
         } else {
             buildConfigField "boolean", "IS_PERFORMANCE_TEST", "false"
         }
+        if (project.hasProperty('force-default-variant')) {
+            buildConfigField "boolean", "FORCE_DEFAULT_VARIANT", "true"
+        } else {
+            buildConfigField "boolean", "FORCE_DEFAULT_VARIANT", "false"
+        }
     }
     buildFeatures {
         viewBinding = true

app/src/main/java/com/duckduckgo/app/buildconfig/RealAppBuildConfig.kt

@@ -52,6 +52,8 @@ class RealAppBuildConfig @Inject constructor() : AppBuildConfig {
         }
     }
     override val isPerformanceTest: Boolean = BuildConfig.IS_PERFORMANCE_TEST
+
+    override val isDefaultVariantForced: Boolean = BuildConfig.FORCE_DEFAULT_VARIANT
     override val deviceLocale: Locale
         get() = Locale.getDefault()
 }

statistics/src/main/java/com/duckduckgo/app/statistics/VariantManager.kt

@@ -208,7 +208,7 @@ class ExperimentationVariantManager(
         var newVariant = generateVariant(activeVariants)
         val compliesWithFilters = newVariant.filterBy(appBuildConfig)
 
-        if (!compliesWithFilters) {
+        if (!compliesWithFilters || appBuildConfig.isDefaultVariantForced) {
             newVariant = DEFAULT_VARIANT
         }
         Timber.i("Current variant is null; allocating new one $newVariant")