Add new RIL requests to support SIM data download via SMS over IMS.

On an LTE device where incoming SMS messages over IMS are sent to
the framework via RIL_UNSOL_RESPONSE_NEW_SMS responses sent to
the RIL, it may be necessary to process USIM data download SM's
(message class 2). This requires the RIL to implement two new requests.

1) RIL_REQUEST_STK_SEND_ENVELOPE_WITH_STATUS:
   send an ENVELOPE command to the UICC, receiving the SW1 and SW2
   status bytes in addition to the command response.

2) RIL_REQUEST_SMS_ACKNOWLEDGE_WITH_PDU:
   send an RP-ACK or RP-ERROR acknowledgement to the incoming SM,
   including an acknowledgement PDU containing the envelope response.

Change-Id: If597a14fa8c4780c75da84fa96c49abcb05960f2