SystemUI: double tap to sleep improvements

* Make it more reliable
* Add it to keyguard
* Add a content observer to not always query Settings.System on every
touch event

Adin's edit: format to follow AOSP Java Code Style

Change-Id: I7fe1f9f9fba446bdc43d818639f6746a8541d072
Signed-off-by: Roman Birg <roman@cyngn.com>
Signed-off-by: Adin Kwok <adin.kwok@carbonrom.org>
Signed-off-by: Josh Fox(XlxFoXxlX) <joshfox87@gmail.com>
Signed-off-by: Mihran Thalhath <mihranz7@gmail.com>
3 files changed