I'm developing a library for the Android and I have a question regarding Android GCM using the new Firebase "model" (FCM). In the old and gold GCM, I could receive push notifications from different senders, since they support this when you request for token registration, as you can see in this method (that now is deprecated): https://developers.google.com/android/reference/com/google/android/gms/gcm/GoogleCloudMessaging.html#register(java.lang.String...)
This method was particularly useful to us, since we have our own backend that communicates with our library. So we have our own Google Project and the user of our library could also send his own notifications to the application too (with it's own Sender ID).
With this new FCM, you have to generate some .json (google-services.json) that contains the Google Project information (and also the Sender ID), and some code will be generated.
My question is, can we still receive in the same onMessageReceived from multiples Sender IDs? I mean, from multiple projects in the same Google/Firebase account I know that it's possible, but in the same application from multiples Firebase accounts is possible? Or I would have to add every application that uses our library in our own Firebase account?
