SystemUI: Add double tap to sleep gesture

Change-Id: I4c54718e8ec8774677d13917b3a7ffa3b4b18cb5
Show live wallpapers in the recents view on high-end devices

Change-Id: Iefbf4f292b6a9bfdb516f154cc2976db2ba86cde
Runtime toggle of navbar

This adds the framework support for enabling the Navigation bar
on devices with hardware keys. It is toggled from Settings, and
depends on device-specific support for the KeyDisabler hardware
control

Change-Id: I88fecb2ca1e8613591c327a93f53909b00239cd8

wm: Nullify hardkey function assignments if enabling the navbar

This caused erroneous (and sometimes duplicate) events being generated
due to the regular key function assignments. The navbar does its
own action management, so don't try to derive from the actions
usually present in hard keys.

Change-Id: I82866e24547f8145cac4f07820ae90aacce09281
Add PowerManager integration for button and keyboard backlight.

Allows setting button and keyboard backlight brightness as well as
button timeout.

Change-Id: I550cccafc0a8f90d6347de9261adb26b75955cc4