Android/obb permission

[SloppyPuppy]

AOSP Image: GrapheneOS 16 (BP3A.251105.015)

Under special app access -> install unknown apps I can check "installation of apps from this source", but it also lets me grant "Allow access to Android/obb folder" to the corresponding app, however despite granting the permission when I try to access Android/obb I get "Root isn't available" exception.

-- A bit of vibecoding later... and I got it to work with this patch. #1501

I saw the copyright notice, in any case, this is just some trash vibecode, but in essence I would like to suggest a change that lets material files on grapheneos (it seems like a more granular permission that is still not in mainstream aosp) actually use Android/obb. With the silly vibecode I was able to read and write to it, if not implementing something like this if aosp upstreams the feature, it would still be nice futureproofing to refactor it in a way that isn't too aggressive with when it checks and attempts to use elevated permissions.