Create API in BackupManagerService for work profile serial id mapping.

The launcher needs to know the serial id of the ancenstral device's work
profile  and the serial id of the current device's work profile in order
to properly perform a restore.

Test: atest BackupManagerService
Bug: 111301511

Change-Id: Ia929dcc2cb599f935183be1820b1c45f2d6e1de7
9 files changed