feat: add MediaGrants to MediaProvider

* Introduce a new helper class to manage the media_grants table.
* Add a MediaStore API to add new MediaGrants via MediaProvider
* Cleanup all package grants when a package is orphaned / removed.
* Update PhotoPickerActivity to add MediaGrants for selected items for
  the calling package.

Bug: 259058623
Bug: 259058885
Test: atest MediaGrantsTest
Change-Id: I13d5cae5528f384310cba46bb737c01c04731e8a
Merged-In: Id225e403d69195165336c94e20d2d291edaae150
6 files changed