Add Android L NavBar Icons

PS 3: Try to fix Pie icons

Change-Id: I80675edb70ffff14ef15119f3b8dde11233b9acb
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
Heads up: option to disable in lockscreen (1/2)

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java

Change-Id: Ib002ebf52ee834968765f9a00356ee45a85adc1e