Introduce AttributionAndPermissionUtils.

The CameraService class is getting large and permission checking is
becoming a large portion of it. Separate this logic out into its own
utils class to make it easier to find code responsible for verifying
client permissions and the identity of the caller.

Bug: 190657833
Test: Smoke testof GCA, CtsCameraTestCases
Change-Id: I305706846db399eb92c8409271fb3e591539032f
12 files changed