chore: Fix examples (#688)

Author: tiwarishubham635

examples/csharp/src/Twilio/Rest/Domain.cs

@@ -15,6 +15,6 @@ public static implicit operator Domain(string value)
         public static readonly Domain FlexApi = new Domain("flex-api");
         public static readonly Domain Versionless = new Domain("versionless");
         public static readonly Domain PreviewIam = new Domain("preview-iam");
-        public static readonly Domain Iam = new Domain("iam");
+        public static readonly Domain Oauth = new Domain("oauth");
     }
 }