Add messageId to both of the MMS methods

There are two MMS-related methods in SmsManager, one to send a
multimedia message and one to download a multimedia message. In
R, a messageId parameter was added to the various SMS sending
methods. The messageId allows for eventual increased reliablility.
The messageId parameter was added to MmsManager for R, but
MmsManager was ultimately hidden in R. This change applies the
same treatment to the two MMS methods in S, that was applied to
the SMS methods in R.

Test: manual testing and atest MmsTest
Bug: 163413552

Change-Id: Ic8e59b652967ab1296a92a1d5727dc226cb190fb