Set the Network Specifier on Emergency SUPL

The sub ID of a SIM that the emergency call
was made on needs to be specified while
requesting a SUPL Emergency connection. This
is done by setting the Network Specifier in
the SUPL Emergency connection request so that
connection is made on the correct sub for a
device that can have more that one SIM.

Bug: 150115901
Change-Id: Id0d85125d1aa8c019ecb8f622b604a6eacec7380
CRs-fixed: 2563763