Make Cloud Media Provider selection dependent on allow list

Introduced a way to control the list of applications that can be used as
cloud media providers based on allow list that can be retrieved from
Device Config. The change is guarded by System Property so that we don't mess up the current scenario until Device Config backend gets
implemented

Bug: 202141342
Test: atest PhotoPickerSyncControllerTest
Change-Id: I800b477ba77b5b45e10f3a453a1bac83f0154e48
5 files changed