kubernetes: [Failing Test] gce-cos-master-reboot (ci-kubernetes-e2e-gci-gce-reboot )

Which jobs are failing: gce-cos-master-reboot (ci-kubernetes-e2e-gci-gce-reboot )

Which test(s) are failing: [k8s.io] [sig-cloud-provider-gcp] Reboot [Disruptive] [Feature:Reboot] each node by switching off the network interface and ensure they function upon switch on

Testgrid link: https://testgrid.k8s.io/sig-release-master-informing#gce-cos-master-reboot

Reason for failure: check https://prow.k8s.io/view/gcs/kubernetes-jenkins/logs/ci-kubernetes-e2e-gci-gce-reboot/1212748364777525249

Anything else we need to know: /cc @kubernetes/ci-signal /milestone v1.18 /sig cloud-provider-gcp