Bring back navbar height settings

Conflicts:
	res/values/purity_arrays.xml
	res/values/purity_strings.xml
	res/xml/lockscreen_interface_settings.xml
	res/xml/purity_system_settings.xml
	res/xml/security_settings_lockscreen.xml
	src/com/android/settings/SecuritySettings.java
	src/com/android/settings/purity/LockscreenInterface.java
Navigation ring customization.

Conflicts:
	res/values/purity_strings.xml
	res/xml/purity_system_settings.xml
Navbar & Navring compatibility with PA(MUST cherry-pick)
Modify Navbar Settings

-Move Navbar Height Settings to DisplaySettings.java
-Remove navbar & navring settings drawables.