fix stop_grace_period in v3 (#1300)

script/test/fixtures/v3/output-k8s-full-example.json

@@ -367,6 +367,7 @@
           }
         ],
         "restartPolicy": "OnFailure",
+        "terminationGracePeriodSeconds": 20,
         "hostname": "foo",
         "subdomain": "foo.com"
       },

script/test/fixtures/v3/output-os-full-example.json

@@ -367,6 +367,7 @@
           }
         ],
         "restartPolicy": "OnFailure",
+	"terminationGracePeriodSeconds": 20,
         "hostname": "foo",
         "subdomain": "foo.com"
       },