Fix multi-user behaviour for system UI settings (1/2)

Change-Id: I0e434b989c16f5871ce56c7e3041ff3c7a436c73

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/NavigationButtons.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/BatteryController.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java