Revert "NavigationBar : Customization"

This reverts commit 2c1fe25bf91f939f91cda2fd2bd948583f2f60dc.

Conflicts:

	packages/SystemUI/res/layout-sw600dp/mid_navigation_bar_land.xml
	packages/SystemUI/res/layout-sw600dp/mid_navigation_bar_port.xml
	packages/SystemUI/res/layout/mid_navigation_bar_land.xml
	packages/SystemUI/res/layout/navigation_bar.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavbarEditor.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java