style(LargeVideo): Rename LARGE_VIDEO_AVATAR_DISPLAYED event

modules/UI/ring_overlay/RingOverlay.js

 let overlay = null;
 
 /**
- * Handler for UIEvents.LARGE_VIDEO_AVATAR_DISPLAYED event.
+ * Handler for UIEvents.LARGE_VIDEO_AVATAR_VISIBLE event.
  * @param {boolean} shown indicates whether the avatar on the large video is
  *  currently displayed or not.
  */
         $(`#${this._containerId}`).remove();
     }
 
+    /**
+     * Stops the ringing and clears related timers.
+     */
     _stopAudio() {
         if (this.interval) {
             clearInterval(this.interval);
         }
 
         overlay = new RingOverlay(callee, disableRingingSound);
-        APP.UI.addListener(UIEvents.LARGE_VIDEO_AVATAR_DISPLAYED,
+        APP.UI.addListener(UIEvents.LARGE_VIDEO_AVATAR_VISIBLE,
             onAvatarDisplayed);
     },
 
         }
         overlay.destroy();
         overlay = null;
-        APP.UI.removeListener(UIEvents.LARGE_VIDEO_AVATAR_DISPLAYED,
+        APP.UI.removeListener(UIEvents.LARGE_VIDEO_AVATAR_VISIBLE,
             onAvatarDisplayed);
         return true;
     },

modules/UI/videolayout/VideoContainer.js

         this.$avatar.css("visibility", show ? "visible" : "hidden");
         this.avatarDisplayed = show;
 
-        this.emitter.emit(UIEvents.LARGE_VIDEO_AVATAR_DISPLAYED, show);
+        this.emitter.emit(UIEvents.LARGE_VIDEO_AVATAR_VISIBLE, show);
     }
 
     /**

service/UI/UIEvents.js

     /**
      * Notifies that the avatar is displayed or not on the largeVideo.
      */
-    LARGE_VIDEO_AVATAR_DISPLAYED: "UI.large_video_avatar_displayed",
-    
+    LARGE_VIDEO_AVATAR_VISIBLE: "UI.large_video_avatar_visible",
+
     /**
      * Toggling room lock
      */