joinSuccess2RemoteJoined property

If the local user calls startMediaRenderingTracing before successfully joining the channel, this value is the time interval (ms) from the local user successfully joining the channel to the remote user joining the channel. If the local user calls startMediaRenderingTracing after successfully joining the channel, the value is the time interval (ms) from startMediaRenderingTracing to when the remote user joins the channel. If the local user calls startMediaRenderingTracing after the remote user joins the channel, the value is 0 and meaningless. In order to reduce the time of rendering the first frame for remote users, Agora recommends that the local user joins the channel when the remote user is in the channel to reduce this value.