provide default value for uuid formats (DataDog#2915)

Author: nogates

.generator/conftest.py

@@ -345,6 +345,7 @@ def request_parameter(context, operation_id, api_version, operation_specs, name,
                     value = {
                         "string": {
                             "date-time": "2021-11-11T11:11:11.111+00:00",
+                            "uuid": "9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d",
                             None: name,
                         },
                         "integer": {