ref(video-quality): Resolve sender operations when RTCRtpSender/RTCRtpSendParameters are not found.

The constraints are applied again after renegotiation is done. This should mitigate a fail case on Safari when the RTCRtpSendParameters are not available until the simulcast streams are added via SDP munging before sLD is called.

modules/RTC/TraceablePeerConnection.js

     const videoSender = this.findSenderByKind(MediaType.VIDEO);
 
     if (!videoSender) {
-        return Promise.reject(new Error('RTCRtpSender not found for local video'));
+        return Promise.resolve();
     }
     const parameters = videoSender.getParameters();
 
     if (!(parameters.encodings && parameters.encodings.length)) {
-        return Promise.reject(new Error('RTCRtpEncodingParameters not found for local video'));
+        return Promise.resolve();
     }
 
     if (this.isSimulcastOn()) {
     const videoSender = this.findSenderByKind(MediaType.VIDEO);
 
     if (!videoSender) {
-        return Promise.reject(new Error('RTCRtpSender not found for local video'));
+        return Promise.resolve();
     }
     const parameters = videoSender.getParameters();
 
     if (!parameters || !parameters.encodings || !parameters.encodings.length) {
-        return Promise.reject(new Error('RTCRtpSendParameters not found for local video track'));
+        return Promise.resolve();
     }
 
     if (this.isSimulcastOn()) {