SystemUI: Use EdgeGesture service to trigger Pie

EdgeGesture service triggers Pie when detecting gestures on
the WHOLE edge, not just the center.

Patch Set 2: Better trigger values

Change-Id: Id7d9d7f6f5a37ca3696cdddf0da78c88c067970e
Merge "SystemUI: Use EdgeGesture service to trigger Pie" into kitkat