commit 67c41fddd8926f70774878e5af70a9cb81393641
author Hyundo Moon <hdmoon@google.com> Fri Jan 17 14:22:42 2020 +0900
committer Hyundo Moon <hdmoon@google.com> Sun Jan 19 16:03:52 2020 +0900
tree 5dac13f67368b8ecdf22af44ffd1f51b5b1cd0db
parent 4b083362890edbe54f704144a5149d6168ee7529

MediaRouter2: Add getDefaultController()

The controller which can control the system routes (phone speaker,
bluetooth, etc) is returned by this new method.

This CL makes the default controller can know the current system route,
and make SessionCallback#onSessionInfoChanged() be called when
the current system route is changed.

Note that selecting route (BT / speaker) via this controller is not
yet supported by this CL.

Bug: 147937954
Test: atest mediaroutertest
      Also, manually checked logs by connecting bluetooth device.
Change-Id: I8c6254855f8121d1d2331959224fe7237affa1e2