Use dl.k8s.io instead of hardcoded GCS URIs

The `storage.googleapis.com/kubernetes-release` URL is a hard coded path
to a GCS bucket location. To allow redirecting and spreading the load
across multiple hosting locations, the `dl.k8s.io` URL has been
introduced.

Signed-off-by: Sean McGinnis <stmcg@amazon.com>

hack/ensure-kubectl.sh

@@ -31,7 +31,7 @@ verify_kubectl_version() {
         mkdir -p "${GOPATH_BIN}"
       fi
       echo 'kubectl not found, installing'
-      curl -sLo "${GOPATH_BIN}/kubectl" https://storage.googleapis.com/kubernetes-release/release/${MINIMUM_KUBECTL_VERSION}/bin/linux/amd64/kubectl
+      curl -sLo "${GOPATH_BIN}/kubectl" https://dl.k8s.io/release/${MINIMUM_KUBECTL_VERSION}/bin/linux/amd64/kubectl
       chmod +x "${GOPATH_BIN}/kubectl"
     else
       echo "Missing required binary in path: kubectl"