Frameworks: Specify notification types for Auto Hide statusbar (1/2)

Allows users to choose between "non-permanent only" and "all notifications" in the autohide
the statusbar when there are no notifications check.

- cleanup a bit
- reduce method and provider settings call

Change-Id: I3729c11366e55e5ef4c2ff0ea9931e7e2f5cf5bf

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java