Merge changes from topic 'headsup'

* changes:
  Finishing up heads up changes
  Added the heads up scrim back
  Fixed a bug where a notification could not be collapsed
  Made ranking consistent with heads Up manager
  Fixed a bug where the intrinsic height was not updated
  Fixed more heads up bugs
  More Heads Up bug fixes
  Adapted the interpolator of the heads up appear motion
  Treating headsUpViews now as real notification citizen
  Handling a few more border cases with HUNs
  Integrate Heads-up notifications into the shade
  Fixed a bug with notification clipping