IMS: Use proper phone to route emergency calls

-- By default emergency calls will be dialed using ImsPhone.
   For multi-sim use cases if tried to dial emergency calls
   using ImsPhone where feature state is NOT_READY then will
   end up in not sending DIAL request to lower layers as
   ImsServiceProxy will not allow creating call profile if
   feature state is NOT_READY.
-- Check feature state before routing emergency calls to ImsPhone.

Change-Id: I92d3802bdf57e72689d4e52d6a17e391ef52f8d2
CRs-Fixed: 2078200