Revert k8s.gcr.io vanity domain

This reverts commit eba5b6092a.

Fixes https://github.com/kubernetes/kubernetes/issues/57526

examples/kubectl-container/Makefile

@@ -37,11 +37,11 @@ tag: .tag
 
 container:
 	$(if $(TAG),,$(error TAG is not defined. Use 'make tag' to see a suggestion))
-	docker build --pull -t k8s.gcr.io/kubectl:$(TAG) .
+	docker build --pull -t gcr.io/google_containers/kubectl:$(TAG) .
 
 push: container
 	$(if $(TAG),,$(error TAG is not defined. Use 'make tag' to see a suggestion))
-	gcloud docker -- push k8s.gcr.io/kubectl:$(TAG)
+	gcloud docker -- push gcr.io/google_containers/kubectl:$(TAG)
 
 clean:
 	rm -f kubectl

examples/kubectl-container/pod.json

@@ -8,7 +8,7 @@
     "containers": [
       {
         "name": "bb",
-        "image": "k8s.gcr.io/busybox",
+        "image": "gcr.io/google_containers/busybox",
         "command": [
           "sh", "-c", "sleep 5; wget -O - ${KUBERNETES_RO_SERVICE_HOST}:${KUBERNETES_RO_SERVICE_PORT}/api/v1/pods/; sleep 10000"
         ],
@@ -36,7 +36,7 @@
       },
       {
         "name": "kubectl",
-        "image": "k8s.gcr.io/kubectl:v0.18.0-120-gaeb4ac55ad12b1-dirty",
+        "image": "gcr.io/google_containers/kubectl:v0.18.0-120-gaeb4ac55ad12b1-dirty",
         "imagePullPolicy": "Always",
         "args": [
           "proxy", "-p", "8001"