Push notifications in Android rely on Google Cloud Messaging (GCM). When setting up your app, you also need to register with GCM in order to receive push notifications from the M3 backend.
To do so, follow the steps that can be found in Googles official documentation at:
- Create a project on Firebase console
- Choose 'Add Firebase to Android app'
- In the Firebase console, the package name should be the same as application id in build.grade
- The Firebase console creates a google-services.json file and downloads it to your default Downloads folder. Drag the downloaded google-services.json file to your Android project (as documented in https://developers.google.com/cloud-messaging/android/client)
- Add the sender id to build.gradle of the app
- In the MAAS portal, for the newly created Android app, replace the API Key and sender id with the values for ServerKey and SenderId on the Firebase console (under CloudMessaging section)