Add new background location APIs.

Work on issue #109754053: Implement tri-state location in platform

- New background location permission
- New (temporary?) API level for compatibility with old apps

None of this is exposed yet as a public API, that will be
done in the future.

Bug: 109754053
Test: atest FrameworksServicesTests:AppOpsServiceTest
Test: atest CtsPermissionTestCases:AppOpsTest
Change-Id: I986dc871b9e8ed3bf592d2546eadaefb4fefe099