apparently this is closer to the material design specs:
https://m2.material.io/components/checkboxes#usage

so they can be shown when selecting apps for restore which is before we have downloaded the APK files to extract icons from

this is helpful for restore, so the user can see app names when deciding which apps to restore

see seedvault-app@5662409

system data comes first and then apps

This way we don't need to show the long complicated list, but provide an all or nothing option at least.

While we still don't guarantee that an attacker with access to the storage can't find out which apps we use (APKs are still unencrypted after all), we go into this direction.

Also, this should make it impossible for an attacker that can modify files to replace or otherwise mess with the icons.

Resources$NotFoundException: Resource ID #0x7f060258 type #0x2 is not valid

during restore process. These can usually not be manually installed anyway and just clutter the list making it harder for the user to find their important apps and potential failures there.

AppDataRestoreManager

which was in RestoreViewModel before.
Now all three steps of app restore have their own dedicated manager class making the ViewModel more readable.

Apps are now restored alphabetically to be consistent with the other lists. Some irrelevant apps are hidden. Under the hood, we now use an AsyncListDiffer like in the other lists.

it doesn't really exist and should probably not even be in the backup metadata. It messes up progress reporting, if we keep it in.

We still don't know why, but after latest test fixes, the @pm@ package didn't have the the @meta@ key in the backup, but it did in restore.