Put system live audio only routes at bottom of MediaRouteChooserDialog

We don't yet have a way to tell whether a given media route includes a
bluetooth endpoint. This code change tries to make the best guess based
on the currently available route information only. Future work, possibly
API changes might be required to make route sorting more accurate.

Bug: 23116377
Change-Id: Iad2b3fd8ef7f650b96ca94d6686c7dd0e12ae661
2 files changed