Add background. Add fading enable/disable. Add track switching. Change-Id: Ia3495a6ce98498c734cb225bec93403ac734c89c
Change-Id: I38e8a85d5a7ae30b1c0ee71cff979456bdac0665
SupportLeanbackDemos starts out with a fully functional app with a BrowseFragment. Still need to add examples with cursors, hovercards, and more. Change-Id: I845d5b92c29a5585af7968b08e7daa11b2996f5a