title: GCM Push Notification only works with Debug apk
body: <p>I have gotten reports that my app does not send or receive notifications from users. When I run the app from Android Studio and send a notification to one of my devices that also has a debug version of the apk, I noticed it works fine. Both devices can receive and send notifications as expected. However when I try to run the same test with versions of the app from the Play Store, no notifications are sent or received. I have debugged this and found out that if I am trying to send a notification to a phone that has the Play Store version from a phone that has a debug version, the data sends but the phone with the debug version of the app does not receive the notification. Why is this and how do I fix?</p>