Move more items between layout and animate sides.

- Isolate DimAnimator animation from the layout side.
- Isolate mWallpaperForceHidingChanged and mOrientationChangeComplete
  from the animation side.
- Eliminate a redundant setting of mOrientationChangeComplete to true.
  It was already true at that point.
- Synchronize changes to mWindows and mAppTokens on mAnimator. This is
  a nop until we go to multiple threads.
- Synchronize AppWindowToken.freezingScreen on mAnimator.
- Modification to repeat layout debugging including temporary enabling
  of spew on layout repeats.

Change-Id: Ic8d82b1c197144aaf6957caa5f71e175288220f2