IMS: Support For Per-Call RAT Info
IMS: Support For Per-Call RAT Info

Adding the extra key that will be used to
propagate RAT information for each call via
call extras. The key is used in IMS Service.

Bug: 20144385
Change-Id: Ia7ca81d661afb579fd25315036c43489b1dca50d

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base