Move permission backup into permission controller

As runtime permissions are complex, all runtime permission code is
consolidated into the permission controller app.

Hence the package manager service's permission backup code is now
calling into the PermissionControllerManager which is a interface to the
permission controller app.

Bug: 120907838
Test: Triggered a backup and checked the result via the debugger.
Change-Id: I633162189b728921d902050eee125b4b40b618fd