Turn on webdx features cron (#4727)

cron.yaml

@@ -44,7 +44,6 @@ cron:
 - description: Check if any origin trials require activation
   url: /cron/activate_origin_trials
   schedule: every day 9:00
-# TODO(kyleju): Activate this when it is ready.
-# - description: Fetch a new copy of Webdx feature ID list
-#  url: /cron/fetch_webdx_feature_ids
-#  schedule: every day 9:00
+- description: Fetch a new copy of Webdx feature ID list
+  url: /cron/fetch_webdx_feature_ids
+  schedule: every day 9:00