use object type instead of checking kind

lib/src/participant/local_participant.dart

@@ -242,11 +242,15 @@ class LocalParticipant extends Participant {
 
   @override
   List<LocalTrackPublication<LocalVideoTrack>> get videoTracks =>
-      super.videoTracks.cast<LocalTrackPublication<LocalVideoTrack>>();
+      trackPublications.values
+          .whereType<LocalTrackPublication<LocalVideoTrack>>()
+          .toList();
 
   @override
   List<LocalTrackPublication<LocalAudioTrack>> get audioTracks =>
-      super.audioTracks.cast<LocalTrackPublication<LocalAudioTrack>>();
+      trackPublications.values
+          .whereType<LocalTrackPublication<LocalAudioTrack>>()
+          .toList();
 }
 
 extension LocalParticipantTrackSourceExt on LocalParticipant {

lib/src/participant/participant.dart

@@ -77,13 +77,11 @@ abstract class Participant extends DisposableChangeNotifier
   List<TrackPublication> get subscribedTracks =>
       trackPublications.values.where((e) => e.subscribed).toList();
 
-  List<TrackPublication> get videoTracks => trackPublications.values
+  // Must be implemented by child class
-      .where((e) => e.kind == lk_models.TrackType.VIDEO)
+  List<TrackPublication> get videoTracks;
-      .toList();
 
-  List<TrackPublication> get audioTracks => trackPublications.values
+  // Must be implemented by child class
-      .where((e) => e.kind == lk_models.TrackType.AUDIO)
+  List<TrackPublication> get audioTracks;
-      .toList();
 
   /// for internal use
   /// {@nodoc}

lib/src/participant/remote_participant.dart

@@ -27,11 +27,15 @@ class RemoteParticipant extends Participant {
 
   @override
   List<RemoteTrackPublication<RemoteVideoTrack>> get videoTracks =>
-      super.videoTracks.cast<RemoteTrackPublication<RemoteVideoTrack>>();
+      trackPublications.values
+          .whereType<RemoteTrackPublication<RemoteVideoTrack>>()
+          .toList();
 
   @override
   List<RemoteTrackPublication<RemoteAudioTrack>> get audioTracks =>
-      super.audioTracks.cast<RemoteTrackPublication<RemoteAudioTrack>>();
+      trackPublications.values
+          .whereType<RemoteTrackPublication<RemoteAudioTrack>>()
+          .toList();
 
   RemoteParticipant(
     this._engine,