Extract the remote addresses from SDP c= line on both session level and media level. The media level address will overwrite the session level one if exists. WebRTC is not using c= and this is used for new SDP parsing API. BUG=webrtc:7311 Review-Url: https://codereview.webrtc.org/2742903002 Cr-Commit-Position: refs/heads/master@{#17326}