Allow voice search on connected physical remote

- "active" state exists for only 5 seconds after the first button is
   pressed.
- this state does not get reset when mashing any other button,
  including the voice search button.
- "connected" state exists for approx. 30 seconds after the last
  button is pressed.
- we force device into submix mode for 5 seconds when virtual remote
  is active (any key is pressed).
- Using these, voice search can be routed from the physical remote
  as long as submix is not being forced AND we have a physical
  remote in "connected" state.

b/26455183

Change-Id: I80962b6bb06789c31d414bbacfdac6633d6c9645
1 file changed