Wallpaper Overscroll and Transparent NavBar

Now possible to offset wallpaper windows by more than the size of the wallpaper
and add added a transparent mode to the NavigationBar

Change-Id: I2b0f1129a4cf73b8def35abb7072d0472a9cc972

Conflicts:

	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	services/java/com/android/server/wm/Session.java
Keyguard: more consistency with the new lockscreen wallpaper

* In the case when the screen was off and setCustomDrawable()
was being called, and the use wallpaper is null, then we could be
setting the color filter on a null drawable.

* Fix logic when old custom background was null and the new one is also
null (but could be the user one) and the func was being returned, thus not
clearing out the current media album art.

* Move resetting the shouldShowWallpaper() flag to the show() method
so it is not being called every time the screen is turned on.

* Fix user image not showing up on first boot if it exists

Change-Id: I567c2ec8920df627835defb822c2ea25be7b3cab
Signed-off-by: Roman Birg <roman@cyngn.com>
wallpaper: add missing @hides

Add missing @hides to setWallpaperOverscroll and setWallpaperOverscrollOffsets

Change-Id: I1cfe876272d7c0a94bef122567da30318eac9400
Keyguard : Fix album art sticking after playback is stopped

newIsNull should be populated by what is currently being set and not by
what the user's custom background is, since otherwise you end up a in state
where the user has no custom background set, music stops, no album art via arg is provided and you simply return.

Change-Id: Ifaea1cae176faaba6b32a711071f3b75ccacdd63