HOVER: Implement hide only on swipe up

* Add an Y axis HideHelper, just extend current X axis SwipeHelper and
  change interested methods behaviors
* Some clean up and indenting

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I42a260ea993c614b0b9b4558a95dd44dd517c4f1
Update the volume panel color to match Hover