Only remountUid when uid is active

StorageManagerService may get appops or permission change callbacks
requiring it to remount the storage volumes for a certain uid.

Now, we ignore this expensive call for uids without any active processes

Test: Logs show many calls being ignored
Bug: 141678467

Change-Id: I66e28d0e4107f6eb6abda78eb59039549b7bc670
1 file changed