fix: fix monitorStats not started when sender == null. (#606)

* fix: fix monitorStats not start when sender == null.

* set some log levels to lower.

* update.

example/lib/pages/room.dart

@@ -87,7 +87,6 @@ class _RoomPageState extends State<RoomPage> {
           (timeStamp) => Navigator.popUntil(context, (route) => route.isFirst));
     })
     ..on<ParticipantEvent>((event) {
-      print('Participant event');
       // sort participants on many track events as noted in documentation linked above
       _sortParticipants();
     })

lib/src/core/room.dart

@@ -137,7 +137,7 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
 
     // Any event emitted will trigger ChangeNotifier
     events.listen((event) {
-      logger.fine('[RoomEvent] $event, will notifyListeners()');
+      logger.finer('[RoomEvent] $event, will notifyListeners()');
       notifyListeners();
     });
 

lib/src/participant/participant.dart

@@ -140,7 +140,7 @@ abstract class Participant<T extends TrackPublication>
   }) : _name = name {
     // Any event emitted will trigger ChangeNotifier
     events.listen((event) {
-      logger.fine('[ParticipantEvent] $event, will notifyListeners()');
+      logger.finer('[ParticipantEvent] $event, will notifyListeners()');
       notifyListeners();
     });
 

lib/src/publication/remote.dart

@@ -213,7 +213,7 @@ class RemoteTrackPublication<T extends RemoteTrack>
         );
 
         newValue.onVideoViewBuild = (_) {
-          logger.fine('[Visibility] VideoView did build');
+          logger.finer('[Visibility] VideoView did build');
           if (_lastSentTrackSettings?.disabled == true) {
             // quick enable
             _cancelPendingTrackSettingsUpdateRequest?.call();

lib/src/track/local/audio.dart

@@ -52,7 +52,7 @@ class LocalAudioTrack extends LocalTrack
 
   @override
   Future<bool> monitorStats() async {
-    if (sender == null || events.isDisposed || !isActive) {
+    if (events.isDisposed || !isActive) {
       _currentBitrate = 0;
       return false;
     }

lib/src/track/local/video.dart

@@ -67,7 +67,7 @@ class LocalVideoTrack extends LocalTrack with VideoTrack {
 
   @override
   Future<bool> monitorStats() async {
-    if (sender == null || events.isDisposed || !isActive) {
+    if (events.isDisposed || !isActive) {
       _currentBitrate = 0;
       return false;
     }

lib/src/track/track.dart

@@ -63,7 +63,7 @@ abstract class Track extends DisposableChangeNotifier
       {this.receiver}) {
     // Any event emitted will trigger ChangeNotifier
     events.listen((event) {
-      logger.fine('[TrackEvent] $event, will notifyListeners()');
+      logger.finer('[TrackEvent] $event, will notifyListeners()');
       notifyListeners();
     });