Update/Add method on InfoMediaManager

This CL include following change:

- Filter out non system route on getAllRoutes().
- Add releaseSession() to release session to stop playing media
  on MediaDevice.
- Add test case.

Bug: 149896648
Test: make -j42 RunSettingsLibRoboTests
Change-Id: Ibed6e22a8b01d5e1a3c92a80f569b21f40441c27
3 files changed