Make Auto Revoke LiveData syncronous

The update method does not load any system data, and the async nature
was causing concurrentModificationExceptions in tests, due to multiple
threads reading and writing the same map.

Test: Atest GooglePermissionControllerUnitTests:ManageStandardPermissionsFragmentTest
Fixes: 155802480
Change-Id: I356646645e4b2169842db4f4064cb4a966058777