notification_open never reported if onCreate of MainActivity was not called

* Android Studio version: Android Studio Chipmunk | 2021.2.1
* Firebase Component: Firebase Cloud Messaging
* Component version: 23.0.5

### Problems
My app has only one `MainActivity`, and it's singleTask.
When I received the notification and tap it to bring my app to foreground, the `MainActivity` was not recreated and its `onCreate` method was not called.
So `FcmLifecycleCallbacks` had no chance to report the notification_open event.

#### Steps to reproduce:
1. Make the `MainActivity` singleTask, and don't call `finish`, just send it to background
2. Enable Firebase Analytics debug, and open the DebugView
3. Push a notification to the device
4. Make sure we can see the notification_receive event in the DebugView
5. Tap the notification to open the App
6. notification_open event won't show in the DebugView

#### Relevant Code:

`FcmLifecycleCallbacks`
code below will never be called
```
@Override
public void onActivityCreated(Activity createdActivity, Bundle instanceState) {
Intent startingIntent = createdActivity.getIntent();
if (startingIntent == null || !seenIntents.add(startingIntent)) {
// already seen (and logged) this, no need to go any further.
return;
}

if (VERSION.SDK_INT <= VERSION_CODES.N_MR1) {
// On Android 7.1 and lower Bundle unparceling is not thread safe. Wait to log notification
// open after Activity.onCreate() has completed to try to avoid race conditions with other
// code that may be trying to access the Intent extras Bundle in onCreate() on a different
// thread.
new Handler(Looper.getMainLooper()).post(() -> logNotificationOpen(startingIntent));
} else {
logNotificationOpen(startingIntent);
}
}
```