LegacyUSB: Squashed commit with updates for 4.3

LegacyUSB: add overlay for UMS lun and use existence of lun to enable legacy USB

LegacyUSB: Add support for legacy USB implementations

Rebased for JB 4.3

Option to hide Adb notification icon (framework) - authorship belongs to Rick C

Change-Id: Id14f70f7e21b689c08cadef69f69da711c7dc566

Conflicts:

	core/res/res/values/config.xml
	core/res/res/values/symbols.xml

Conflicts:
	core/res/res/values/symbols.xml