SystemUI: Materialize volume panel in/out animation

* Thanks to @David96 that had the original idea, material
  oriented, already during kitkat times.

Signed-off-by: BigBrother1984 <carlosavignano@aospa.co>
Change-Id: Ic79d404c4a0d5bc0a83d20cd4e0d7d5ad7b7c90f

Conflicts:
	packages/SystemUI/src/com/android/systemui/volume/VolumePanel.java

Conflicts:
	packages/SystemUI/src/com/android/systemui/volume/VolumePanel.java

Conflicts:
	packages/SystemUI/src/com/android/systemui/volume/VolumePanel.java