Refactor Geocoder Provider System APIs

1) Deprecate old GeocoderProvider API which is not part of any published
   API surface.
2) Create new GeocoderProviderBase API which lives in normal SystemApi
   surface.
3) Cleanup various callback APIs and geocoding POJOs used internally.

Bug: 279319276
Bug: 229872126
Test: CTS
Change-Id: I1da453ba5f9fd98b08ecdbbbacf640497ed6cd42