fixup! RadioMessagingProxy: Fix sending CDMA IMS SMS

There is no real fix here as the underlying value is the same
in AIDL and HIDL HALs.

This also removes the default tech assignment to GSM
and only does that in case the PDU is for GSM as they
are/should be mutually exclusive.

Change-Id: I92a999748c6873e72e669d866e304b6314e8d51d