Set reject duplicates bit on SMS pdu for IMS fallback

When performing an IMS fallback to GSM, enable the TP-RD bit
on the outgoing PDU so that we do not accidently send duplicate
messages to the network.

Bug: 111314846
Test: atest FrameworksTelephonyTests:ImsSmsDispatcherTest
Change-Id: I91f2e6f3e74b2fbc5a87566a51d06e96962b3e28