Send outbound messages via the default carrier app. Initially, the

message will go into a pending state. There is a new API call to
update the status of a message. If the carrier app cannot send the
message, it will fall back to the default GSM/CDMA network.

This is the same cl as 476721 which has already been approved by jsh@

Change-Id: I51d732b9cc40b371f77fd26d28e0836a466afc71