More granular control over "App backup" option

[TinfoilSubmarine]

Hi, I find the "App backup" functionality to be a good thing to do. However, it does make the size of the backup increase considerably.

A thought I had on a compromise that might be interesting for some users is to allow users to select which apps they would like to back up the APK of. The use case would be this: if there are certain apps that have been or may be de-listed from the app store they were installed from, the user can opt those apps into app backup. But for apps that are open-source, available on F-Droid, etc. the user may decide that the risk of this app completely disappearing is low enough that they don't need to back it up.