1. Move management of the remote fill service in a dedicated
class that abstracts away the async and ephemeral nature
of the binding.
2. Update auth to move fingerprint out of the platform and
allow response and dataset auth.
3. Cleaned up the fill and save callback classes.
4. The UI is now shared among all sessions and cleaned up.
5. Reshuffled the remote callbacks to have cleaner separation.
6. Cleaned up and tightened the reponse and dataset classes.
7. Added API to support communicationn with intent based auth.
Test: CTS + manually
bug:31001899
Change-Id: Idc924a01d1aea82807e0397ff7293d2b8470d4d6
0f4928f1f7