Add Android L NavBar Icons

PS 3: Try to fix Pie icons

Change-Id: I80675edb70ffff14ef15119f3b8dde11233b9acb
Add a transparent icon to get rid of the camera widget icon on home screen
Don't read configs on every touch event for double tap to sleep

Got the idea from Dave Kessler - VanirAOSP

Change-Id: Ice60896dbd0bcd2de1dbff07baa7bf60af0cad58
[1/2] Statusbar: Make double tap gesture configurable

Change-Id: I6864f54bd4fa1616910135efd82015e9d8c08659

Observe double tap gesture setting changes

Change-Id: I51f0e909c1c62eb860297cbdf26cffdb92969a60