[RN] Update WebRTC polyfills

react/features/base/lib-jitsi-meet/native/polyfills-webrtc.js

     MediaStreamTrack,
     RTCSessionDescription,
     RTCIceCandidate,
-    getUserMedia
+    mediaDevices
 } from 'react-native-webrtc';
 
 import RTCPeerConnection from './RTCPeerConnection';
 
 (global => {
-    if (typeof global.webkitMediaStream === 'undefined') {
-        global.webkitMediaStream = MediaStream;
+    if (typeof global.MediaStream === 'undefined') {
+        global.MediaStream = MediaStream;
     }
     if (typeof global.MediaStreamTrack === 'undefined') {
         global.MediaStreamTrack = MediaStreamTrack;
     if (typeof global.RTCPeerConnection === 'undefined') {
         global.RTCPeerConnection = RTCPeerConnection;
     }
-    if (typeof global.webkitRTCPeerConnection === 'undefined') {
+    if (typeof global.RTCPeerConnection === 'undefined') {
         global.webkitRTCPeerConnection = RTCPeerConnection;
     }
     if (typeof global.RTCSessionDescription === 'undefined') {
     const navigator = global.navigator;
 
     if (navigator) {
-        if (typeof navigator.webkitGetUserMedia === 'undefined') {
-            navigator.webkitGetUserMedia = getUserMedia;
+        if (typeof navigator.mediaDevices === 'undefined') {
+            navigator.mediaDevices = mediaDevices;
         }
     }