change notificationType to NotificationType

Map/NotificationServiceMap.cs

@@ -120,7 +120,7 @@ namespace FlutterCodeGenerator.Map
             dartString.AppendLine("\t\treturn model;");
             dartString.AppendLine("\t}");
             dartString.AppendLine($"\tstatic {_notificationEnumModelType.Name_Upper} decodeType(Map<String, dynamic> map) {{");
-            dartString.AppendLine("\t\tfinal typeInt = map['notificationType'] as int;");
+            dartString.AppendLine("\t\tfinal typeInt = map['NotificationType'] as int;");
             dartString.AppendLine($"\t\treturn {_notificationEnumModelType.Name_Upper}.values[typeInt];");
             dartString.AppendLine("\t}");
             dartString.AppendLine("");