Call re-invite - avoid negotiating new ICE media when muting/un-muting the video
Currently, when a re-invite is requested to mute/un-mute the video, a new ICE media (if ICE is enabled) will be negotiated. Renegotiating a new ICE session should be necessary only if the media transport needs to change; for instance, when adding the video to an audio-only call. In most other cases, the current ICE session can be re-used as is.