Bump target SDK to 32
If I'm not mistaken, the only change that affects us is allowBackup=false
not disabling device2device app transfers (which we do to ensure no two devices have the same device ID & certificate).
The full list of changes can be found here: https://developer.android.com/about/versions/12/behavior-changes-12
I haven't jump to SDK 33 because that requires more work (at least: asking for permissions to be able to send notifications).