Media: enables MR2PS to update provider info

With this CL, MediaRoute2ProviderService can update its provider info
and publish its routes.

MediaRouter2Manager.Callback.onProviderUpdated(info) is alao added to
confirm whether correct provider info is sent.

Also, renamed the AIDLs such as
  IMediaRouter2ManagerClient -> IMediaRouter2Manager
  IMediaRoute2Callback -> IMediaRoute2ProviderClient

and changed on** to notify** in AIDLs.

Logics related to selecting/unselecting will be coverd by following CLs.

Test: atest mediaroutertest (after atest mediarouteprovider)

Change-Id: I5b119fbd0622a9422d3edf720b85e296ac4a5694