Fix the profile case with clear app data (#7000)

Fix the profile case with clear app data. Now the app data will clear in
the setup block, instead of the measure block. This also reads the
output to make sure app data has cleared before proceeding to the
measure block.

Author: mrober

firebase-sessions/benchmark/src/main/kotlin/com/google/firebase/benchmark/sessions/StartupBenchmark.kt

@@ -21,6 +21,7 @@ import androidx.benchmark.macro.StartupTimingMetric
 import androidx.benchmark.macro.junit4.MacrobenchmarkRule
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
+import java.io.FileInputStream
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -48,14 +49,25 @@ class StartupBenchmark {
       metrics = listOf(StartupTimingMetric()),
       iterations = 5,
       startupMode = StartupMode.COLD,
+      setupBlock = { clearAppData(packageName) },
     ) {
       pressHome()
+      startActivityAndWait()
+    }
+
+  private fun clearAppData(packageName: String) {
+    val fileDescriptor =
       InstrumentationRegistry.getInstrumentation()
         .uiAutomation
-        .executeShellCommand("pm clear $PACKAGE_NAME")
-        .close()
-      startActivityAndWait()
+        .executeShellCommand("pm clear $packageName")
+    val fileInputStream = FileInputStream(fileDescriptor.fileDescriptor)
+    // Read the output to ensure the app data was cleared successfully
+    val result = fileInputStream.bufferedReader().use { it.readText().trim() }
+    fileDescriptor.close()
+    if (result != "Success") {
+      throw IllegalStateException("Unable to clear app data for $packageName - $result")
     }
+  }
 
   private companion object {
     const val PACKAGE_NAME = "com.google.firebase.testing.sessions"