init: Add net device permission controls for LGE devices

These are used by lge-ril to control the state of the mobiledata
interfaces

Change-Id: Ia869f08564c1f4907240289a32a10e0f3413d8a9a
init: Add a mechanism to extend the property service in device configs

Instead of every so often adding a new set of stuff here for a specific
device, let the device includes overload the property arrays. The
new device_perms.h header documents it

Change-Id: I477e27abebeb4b85abe5fcaf19333999b1625417
Add persist.mac_enforcing_mode property

Conflicts:
	init/property_service.c