fix: Fix selectAudioTrack when using src= (#8857)

Fixes #8856

Author: avelad

lib/player.js

@@ -5891,11 +5891,14 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     };
     const selectSrcEqualsMode = () => {
       if (this.video_ && this.video_.audioTracks) {
+        const LanguageUtils = shaka.util.LanguageUtils;
+        const inputLanguage = LanguageUtils.normalize(audioTrack.language);
         const audioTracks = Array.from(this.video_.audioTracks);
         let trackMatch = null;
         for (const track of audioTracks) {
+          const trackLanguage = track.language || 'und';
           if (track.label == audioTrack.label &&
-              track.language == audioTrack.language &&
+              LanguageUtils.normalize(trackLanguage) == inputLanguage &&
               track.kind == audioTrack.roles[0]) {
             trackMatch = track;
             break;