Removing unnecessary code

- The code was existing before we added onRecentsAnimationStateChanged
  earlier.  But none of the other callers call this method with
  barWindow=NAV_BAR so this code was previously not even getting hit.
  In particular, touchAutoDim is already triggered in the nav bar layout
  touch handling, and the volume panel already listens for touch outside
  so all this does is trigger unnecessary animations (volume
  tries to animate even when not showing, and we don't dim the gesture
  bar since we have the sampling).

Change-Id: I0bb309e1ddb593d01ce8f5fcc9622753324cdd09