Google Play Services 8.4.0 breaks Google Cloud Messaging for Android if iOS is also used

Question

There are several posts that describe aspects of this issue, but there hasn\'t yet been a satisfying answer, so I\'m attempting to collate them all here in hopes of getting

Answer 1

After upgrading version 9.2.1 push notifications displayed by themselves when application is in background (@dblank solution does not work for me)

Workaround: Remove the notification node for Android

{
    "to": "APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx...",
    "notification": {},  //Remove this node when PUSH to Android devices
    "data": {
        "key": "value"
    }
}