Camera: Allow a device to request the focus modes at build time

By default, if a HAL supports touch-to-focus, mode selection is
disabled. Make that an option for devices where manual modes
work better without TTF (Macro, for instance)

Change-Id: I507ea2ba97ab721373ceb405c582ad5ead1b0902

Conflicts:
	res/values/config.xml
	src/com/android/camera/CameraSettings.java