Switch from upstream hyperkube image to individual images

* Kubernetes plans to stop releasing the hyperkube container image
* Upstream will continue to publish `kube-apiserver`, `kube-controller-manager`,
`kube-scheduler`, and `kube-proxy` container images to `k8s.gcr.io`
* Upstream will publish Kubelet only as a binary for distros to package,
either as a DEB/RPM on traditional distros or a container image on
container-optimized operating systems
* Typhoon will package the upstream Kubelet (checksummed) and its
dependencies as a container image for use on CoreOS Container Linux,
Flatcar Linux, and Fedora CoreOS
* Update the Typhoon container image security policy to list
`quay.io/poseidon/kubelet`as an official distributed artifact

Hyperkube: https://github.com/kubernetes/kubernetes/pull/88676
Kubelet Container Image: https://github.com/poseidon/kubelet
Kubelet Quay Repo: https://quay.io/repository/poseidon/kubelet

google-cloud/container-linux/kubernetes/cl/controller.yaml

@@ -90,8 +90,7 @@ systemd:
           --mount volume=var-log,target=/var/log \
           --volume opt-cni-bin,kind=host,source=/opt/cni/bin \
           --mount volume=opt-cni-bin,target=/opt/cni/bin \
-          docker://k8s.gcr.io/hyperkube:v1.17.4 \
-          --exec=/usr/local/bin/kubelet -- \
+          docker://quay.io/poseidon/kubelet:v1.17.4 -- \
           --anonymous-auth=false \
           --authentication-token-webhook \
           --authorization-mode=Webhook \
@@ -134,7 +133,7 @@ systemd:
             --volume script,kind=host,source=/opt/bootstrap/apply \
             --mount volume=script,target=/apply \
             --insecure-options=image \
-            docker://k8s.gcr.io/hyperkube:v1.17.4 \
+            docker://quay.io/poseidon/kubelet:v1.17.4 \
             --net=host \
             --dns=host \
             --exec=/apply