fix(JingleSessionPC) Remove the ssrc lines in remote desc sdp on sour…

…ce removal.

In P2P and unified mode, Chrome does not render the media if an SSRC is removed and the same one is added back (happens when the sender is camera muted->starts SS->stops SS->turns camera on). That is why SSRC was not being removed. However, mobile endpoints that are running in plan-b generate a new SSRC when the client switches between camera and screenshare. This will cause issues on a p2p receiver that is running in unified mode. Fixes jitsi/jitsi-meet#11010.

modules/xmpp/JingleSessionPC.js

@@ -1868,15 +1868,8 @@ export default class JingleSessionPC extends JingleSession {
                     const mid = remoteSdp.media.findIndex(mLine => mLine.includes(line));
 
                     if (mid > -1) {
+                        remoteSdp.media[mid] = remoteSdp.media[mid].replace(`${line}\r\n`, '');
                         if (this.isP2P) {
-                            // Do not remove ssrcs from m-line in p2p mode. If the ssrc is removed and added back to
-                            // the same m-line (on source-add), Chrome/Safari do not render the media even if it is
-                            // being received and decoded from the remote peer. The webrtc spec is not clear about
-                            // m-line re-use and the browser vendors have implemented this differently. Currently work
-                            // around this by changing the media direction, that should be enough for the browser to
-                            // fire the "removetrack" event on the associated MediaStream. Also, the current direction
-                            // of the transceiver for p2p will depend on whether a local sources is added or not. It
-                            // will be 'sendrecv' if the local source is present, 'sendonly' otherwise.
                             const mediaType = SDPUtil.parseMLine(remoteSdp.media[mid].split('\r\n')[0])?.media;
                             const desiredDirection = this.peerconnection.getDesiredMediaDirection(mediaType, false);
 
@@ -1886,7 +1879,6 @@ export default class JingleSessionPC extends JingleSession {
                             });
                         } else {
                             // Jvb connections will have direction set to 'sendonly' for the remote sources.
-                            remoteSdp.media[mid] = remoteSdp.media[mid].replace(`${line}\r\n`, '');
                             remoteSdp.media[mid] = remoteSdp.media[mid]
                                 .replace(`a=${MediaDirection.SENDONLY}`, `a=${MediaDirection.INACTIVE}`);
                         }