Likely ACE vulnerability when restoring backup

[Rudxain]

@0x192

Describe the bug
If a user restores an arbitrary backup, the backup file could run arbitrary adb shell commands on the Android device.

I originally discovered the vulnerability while refactoring UADNG.

See also Universal-Debloater-Alliance/universal-android-debloater-next-generation#760

Expected behavior
The backup file is supposed to declaratively specify the package states

You have a solution?
Check the cmds in the backup file, and only run each one if it changes the package state.

In the meantime, users should only restore backups they created. Never apply the ones from other users