feat(native-participants-pane) volume level state fix

react/features/video-menu/components/native/VolumeSlider.js

         super(props);
 
         this.state = {
-            volumeLevel: (props._volume || 0) * VOLUME_SLIDER_SCALE
+            volumeLevel: props._volume || 0
         };
 
         this._originalVolumeChange = this._onVolumeChange;