fix(index.html): Remove preload attribute on local video tag

index.html

                     <canvas id="dominantSpeakerAudioLevel"></canvas>
                 </div>
                 <div id="largeVideoWrapper">
-                    <video id="largeVideo" muted="true" preload="auto" autoplay></video>
+                    <video id="largeVideo" muted="true" autoplay></video>
                 </div>
                 <span id="videoConnectionMessage"></span>
                 <span id="videoResolutionLabel">HD</span>