Update gcloud versions (#358)

Update latest gcloud versions

Author: google-github-actions-bot

data/versions.json

@@ -491,5 +491,6 @@
   "534.0.0",
   "535.0.0",
   "536.0.0",
-  "536.0.1"
+  "536.0.1",
+  "537.0.0"
 ]