sendTextMessage sometimes appends a message header to the body of the text message

```
a) Before posting your issue you MUST answer to the questions otherwise it
will be rejected (invalid status) by us
b) Please check the issue tacker to avoid duplication
c) Please provide network capture (wireshark) or Android log (DDMS output)
if you want quick response

What steps will reproduce the problem?
1. Use NgnMessagingSession.createOutgoingSession.sendTextMessage

What is the expected output? What do you see instead?
Sometimes the ngn stack will tack another message onto the existing one.

For instance if:

The string you are sending is:

select * from Notifications where TimeUtc
> "2013-03-05T1:43:00Z" and rowid >= 20 limit
20

Sometimes the sip server (freeswitch in this case) will see:

select * from Notifications where TimeUtc
> "2013-03-05T1:43:00Z" and rowid >= 20 limit
20MESSAGE sip:ins_server@nbscab.org SIP/2.0
Via: SIP/2.0/TCP 192.168.1.6:57294;branch=z9hG4bK381342197;rport
From: ;tag=1310373563
To:
Call-ID: 8cae''

As the message body. Notice how after it added MESSAGE...? This
was verified with tcpdump.

What version of the product are you using? On what operating system?
Android Ice Cream Sandwich

Please provide any additional information below.

This doesn't happen all the time. I've verified that the correct string is
being passed to sendTextMessage and that after that the wrong string gets sent
over the wire.
```

Original issue reported on code.google.com by `kjeremy@gmail.com` on 6 Mar 2013 at 5:17