Add additional description stanza names from the old Google Talk protocol...

Add additional description stanza names from the old Google Talk protocol which is used with Google Voice.

(closes issue ASTERISK-20114)
Reported by: Malcolm Davenport


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@369898 65c4cc65-6c06-0410-ace0-fbb531ad65f3