add more user and channel config test

packages/stream_chat/lib/src/core/models/channel_config.dart

@@ -4,7 +4,7 @@ import 'package:stream_chat/src/core/models/command.dart';
 part 'channel_config.g.dart';
 
 /// The class that contains the information about the configuration of a channel
-@JsonSerializable()
+@JsonSerializable(createToJson: false)
 class ChannelConfig {
   /// Constructor used for json serialization
   ChannelConfig({
@@ -87,7 +87,4 @@ class ChannelConfig {
   /// True if urls appears as attachments
   @JsonKey(defaultValue: false)
   final bool urlEnrichment;
-
-  /// Serialize to json
-  Map<String, dynamic> toJson() => _$ChannelConfigToJson(this);
 }

packages/stream_chat/lib/src/core/models/channel_config.g.dart

@@ -32,22 +32,3 @@ ChannelConfig _$ChannelConfigFromJson(Map<String, dynamic> json) {
     urlEnrichment: json['url_enrichment'] as bool? ?? false,
   );
 }
-
-Map<String, dynamic> _$ChannelConfigToJson(ChannelConfig instance) =>
-    <String, dynamic>{
-      'automod': instance.automod,
-      'commands': instance.commands.map((e) => e.toJson()).toList(),
-      'connect_events': instance.connectEvents,
-      'created_at': instance.createdAt.toIso8601String(),
-      'updated_at': instance.updatedAt.toIso8601String(),
-      'max_message_length': instance.maxMessageLength,
-      'message_retention': instance.messageRetention,
-      'mutes': instance.mutes,
-      'reactions': instance.reactions,
-      'read_events': instance.readEvents,
-      'replies': instance.replies,
-      'search': instance.search,
-      'typing_events': instance.typingEvents,
-      'uploads': instance.uploads,
-      'url_enrichment': instance.urlEnrichment,
-    };