Navigation bar buttons customization(2/2)

Navigation bar buttons customization: Padding fix
Fix padding calculation

Navigation bar buttons customization: Fix left over glow
Invalidate all buttons, to avoid nearby glow interference

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/res/layout/navigation_bar.xml
	packages/SystemUI/res/values/ras_strings.xml
Navigation bar custom height(1/2)

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java