Revert "NavigationBar : Customization"

This reverts commit 95d08890d5dbed1fb28057811ae165b7b9f20fcf.

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/res/layout/navigation_bar.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarTransitions.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/KeyButtonView.java