[Android MR] Migrate RemotingMediaRouteProvider to CAF

This CL migrates RemoteMRP to its CAF version. The CL mostly does the class
inheritance from CafBaseMRP. Most logic of CafMRP is reused. The
remoting-specific code include:

* Use RemotingMediaSource when getting MediaSource.
* Use different session controllers.
* Disallow some operations such as joining routes and sending messages

Bug: 711860
Change-Id: Ie00324e0e3066b08a291b35e534f2a4c48e0fb52
Reviewed-on: https://chromium-review.googlesource.com/1220809
Commit-Queue: Zhiqiang Zhang <zqzhang@chromium.org>
Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591075}
6 files changed