title: Initializing multiple FirebaseApp instances within the same Android application
body: <p>Currently we use a single Google Firebase project for push token delivery via FCM in our Android app. We are exploring moving to using 2 separate Firebase projects for different features (and hence the need to initialize 2 separate <code>FirebaseApp</code> instances within the same application). Each FirebaseApp instance would be initialized with credentials/data for the 2 different Firebase projects and each would have separate FCM tokens registered.</p>
  <p>Is this something supported by the Firebase SDK? Any potential concerns with having multiple FirebaseApp instances within the same application?</p>