Improve storage analysis for multi-user/profile ROMs

[d4rken]

When a device has multiple users (extra users, or guest users) and multiple profiles (work-profile, "dual apps", "app cloning"), then the system creates extra paths in private storage (/data/user/11) and public storage (/storage/emulated/999, /data/media/11).

These extra paths are taken into account for global storage size calculations, but when browsing towards apps and user files, the extra data in other users/profiles is not visible. This can be confusing if the global storage values say "10 GB occupied", but then the details show only "3 GB apps, 2GB user files".

With root we can see those extra paths, maybe with ADB (will have to check that).
Best-case would be showing the specific paths, possibly with content (if rooted), and worst-case we show the other potential paths and "guesstimate" what size they are based on the paths we can access and the global storage stats.