[RN] Pollyfill DOMParser

It's required by lib-jitsi-meet when using WebSockets.

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

@@ -99,6 +99,12 @@ function _visitNode(node, callback) {
 (global => {
     const { DOMParser } = require('xmldom');
 
+    // DOMParser
+    //
+    // Required by:
+    // - lib-jitsi-meet requires this if using WebSockets
+    global.DOMParser = DOMParser;
+
     // addEventListener
     //
     // Required by: