group multi-part message by 3gppswappush

If a device only receives part of long SMS from the network,
and then at some time later received another WAP push with
the same msg_id & message_count, device should not try to
combine them as the same message, otherwise it will trigger
out of boundary crash since sequence numbers for concatenated
messages start at 1 and the exception is CDMA WAP PDU messages,
which use a 0-based index. Fix is trying to group long message
by message_count, message_id, address and 3gpp2wap.

Bug: 29773532
Test: runtest --path
frameworks/opt/telephony/tests/telephonytests/src/com/android/internal/telephony/gsm/GsmInboundSmsHandlerTest.java
Change-Id: I18d80f6bad2541e63211b9d61be63d17d817773d