Pie Controls: Fix sound effects.

After the pie service commits, sound effects were broken for
HOME and BACK keys.

This commit fixes this, by moving the play back of the sound
effect from the injection directly to the onClick().

Change-Id: Id59848ccddac20cef80500f6e72d76afa97ae093
Pie controls: Tweaking UX for pie service (1/2)

With the introduction of pie service there is the need to
fine tune the parameters for activation again.

Patch Set #2:
* Base trigger thickness set to 10dp
* User settable activation sensitivity

Patch Set #4:
* Reverted #setSensitivity() in PieGestureTracker
* Added Sensitivity "Very High"

Change-Id: Ief7c1786467195f2ad52dcdb0efd3ad03a48834c

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/PieController.java