Stabalize AmbientContext detection by restoring client requests.

If the underlying detection service restarts or package updates, resume detection for cached requests.

Move cached client data from PerUserService to MasterService, since the former can be re-instantiated when the underlyig detection service gets destroyed.

If the AiAi component is not available, return STATUS_NOT_SUPPORTED.

Bug: 229028987
Test: Flash device and restart/re-install AiAi service to verify detection is restored. Install AiAi apk without detection service, and verify STATUS_NOT_SUPPORTED is returned.
Change-Id: I0b583da07fa0d406c32f0c44a0270f3f81977624