BackupManager runs in the client process, whereas BackupManagerService
runs in the system server process. Therefore, apps permissions need should
be enforced on the service side.
Bug: 158482162
Test: Manually checked that a sample app encounters SecurityException
after but not before this CL, when running code similar to the
sample in http://b/158482162#comment1 to figure out whether
isBackupServiceActive() for its own uid.
Change-Id: I59693819542a80a065a9c88373393b0ba0dbef65
Merged-In: I59693819542a80a065a9c88373393b0ba0dbef65
(cherry picked from commit b2ab2c414f)
79192da3f3