kubernetes: failing test: DNS should provide DNS for ExternalName services

pull-kubernetes-e2e-gke seems to have fallen off a cliff, eg:

https://k8s-gubernator.appspot.com/pr/68629

Or similar in a bunch of PR’s today: https://github.com/kubernetes/kubernetes/pulls?utf8=✓&q=is%3Apr+pull-kubernetes-e2e-gke

Lots of people rolling the /test pull-kubernetes-e2e-gke dice begging for a pass. Symptoms vary run to run so I’m calling it a /kind flake instead of failing test outright.