KustoOperations_List-added def error schema example file in kustooperationlist (Azure#24435)

Author: mmandru

specification/synapse/resource-manager/Microsoft.Synapse/preview/2021-06-01-preview/examples/KustoOperationsList.json

@@ -21,6 +21,14 @@
           }
         ]
       }
+    },
+    "default": {
+      "body": {
+        "error": {
+          "code": "Error code",
+          "message": "Error message"
+        }
+      }
     }
   }
 }