Add RemoteAuthService

Add RemoteAuthService APIs and Stubs (hide) for Settings of D2DA

This CL introduces new SystemApi allow user to discover remote devices
compatible to be registered as remote authenticators via RemoteAuthManager

Design doc: go/remote-auth-manager-fishfood-design

Test: built successfully.
Bug: 290092977
API-Coverage-Bug: 294934095
Change-Id: Iaaae1126065fdc3db469eeb8d85ac654b8199a12