Provision the Android Device for Push
Use this procedure to provision your Android device for Google Play Service Push Notification, Google Cloud Messaging Service (GCM), or Firebase Cloud Messaging (FCM).
In most cases, when you provision the Android Device for Push, you will use the Google Play Services. For more information, see Configuring Google Play Services.
If you are developing an application for devices that do not support Google Play Services, and you are using GCM, you will need to install the Google Cloud Messaging library (gcm.jar). It is an additional library that supports legacy push through Google Cloud Messaging. For more information, see Configuring Google Cloud Messaging.