Add test for /readyz/health endpoint (#476)

* Add test for /readyz/health endpoint

* Update test_model_registry_creation.py

Author: dbasunag

tests/model_registry/python_client/test_model_registry_creation.py

@@ -114,6 +114,9 @@ def test_model_registry_pod_log_mlmd_removal(
             pytest.param(
                 "readyz/isDirty",
             ),
+            pytest.param(
+                "readyz/health",
+            ),
         ],
     )
     def test_model_registry_endpoint_response(