Remove listener when FirebaseApp deleted, and update log messages

Author: mrober

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerformanceInitializer.java

@@ -31,7 +31,10 @@ public void onAppColdStart() {
     try {
       FirebasePerformance.getInstance();
     } catch (IllegalStateException ex) {
-      logger.info("Failed to get instance of FirebasePerformance: %s", ex);
+      logger.info(
+          "FirebaseApp is not initialized. Firebase Performance will not be collecting any "
+              + "performance metrics until initialized. %s",
+          ex);
     }
   }
 }

firebase-sessions/CHANGELOG.md

@@ -1,5 +1,9 @@
 # Unreleased
 
+* [fixed] Made Sessions more resilient to the FirebaseApp instance being deleted.
+
+# 1.0.1
+
 * [fixed] Fixed NPE when no version name is
   set ([#5195](//github.com/firebase/firebase-android-sdk/issues/5195)).
 * [fixed] Populate DataCollectionStatus fields for Crashlytics and Perf.

firebase-sessions/src/main/kotlin/com/google/firebase/sessions/FirebaseSessions.kt

@@ -75,6 +75,11 @@ internal constructor(
     val appContext = firebaseApp.applicationContext.applicationContext
     if (appContext is Application) {
       appContext.registerActivityLifecycleCallbacks(sessionInitiator.activityLifecycleCallbacks)
+
+      firebaseApp.addLifecycleEventListener { _, _ ->
+        Log.w(TAG, "FirebaseApp instance deleted. Sessions library will not collect session data.")
+        appContext.unregisterActivityLifecycleCallbacks(sessionInitiator.activityLifecycleCallbacks)
+      }
     } else {
       Log.e(
         TAG,
@@ -144,7 +149,11 @@ internal constructor(
       sessionCoordinator.attemptLoggingSessionEvent(sessionEvent)
     } catch (ex: IllegalStateException) {
       // This can happen if the app suddenly deletes the instance of FirebaseApp.
-      Log.i(TAG, "Sessions SDK failed to log Session Start event.", ex)
+      Log.i(
+        TAG,
+        "FirebaseApp is not initialized. Sessions library will not collect session data.",
+        ex
+      )
     }
   }