Use participantIdentity instead of Sid for track permissions. (#265)

lib/src/extensions.dart

@@ -161,7 +161,7 @@ extension VideoQualityExt on lk_models.VideoQuality {
 
 extension ParticipantTrackPermissionExt on ParticipantTrackPermission {
   lk_rtc.TrackPermission toPBType() => lk_rtc.TrackPermission(
-        participantSid: participantSid,
+        participantIdentity: participantIdentity,
         allTracks: allTracksAllowed,
         trackSids: allowedTrackSids,
       );

lib/src/types/other.dart

@@ -150,18 +150,18 @@ class RTCIceServer {
 
 @immutable
 class ParticipantTrackPermission {
-  /// The participant id this permission applies to.
-  final String participantSid;
+  /// The participant identity this permission applies to.
+  final String participantIdentity;
 
   /// If set to true, the target participant can subscribe to all tracks from the local participant.
   /// Takes precedence over [allowedTrackSids].
   final bool allTracksAllowed;
 
   /// The list of track ids that the target participant can subscribe to.
-  final List<String> allowedTrackSids;
+  final List<String>? allowedTrackSids;
 
   const ParticipantTrackPermission(
-    this.participantSid,
+    this.participantIdentity,
     this.allTracksAllowed,
     this.allowedTrackSids,
   );