Set up Vold switchable pair to allow swapping internal/external SD

Uncomment the line persist.sys.vold.switchexternal=1 in bulid prop
to use

Change-Id: Ifce2b4317d5e7bc56e2952b588daf4db19075955
Move ro.telephony.ril.v3 to data/local.prop to allow setting change

Change-Id: I95d77f2a3712a630299316792aa57f48101ec315
Use shared defconfig and variant defconfig for command line change

Change-Id: Ic30099ff4ab7b69905947cef42124f979bc78ee0

Conflicts:
	BoardConfig.mk