Windows containers do not include a route to the GCE metadata server by default. This check is causing the "DNS should provide DNS for the cluster" test to fail for clusters with Windows nodes (https://testgrid.k8s.io/sig-windows#gce-windows-master&width=20). Tested that this works by running "DNS should provide DNS for the cluster" against an e2e cluster with Windows nodes brought up on GCE.