Android auto-backup is not supposed to exist on Android 5.1, but I can still run the following command:
adb shell bmgr fullbackup <PACKAGE>
on Android 5.1. Why does it exist in Android 5.1 if auto-backup isn't available? What does it do? The same as on Android 6?
Also what is @pm@ and why do we need to do it for auto-backup:
adb shell bmgr backup @pm@ && adb shell bmgr run
For reference: Testing Android Backup