Declare etcd data directory permissions

* Set etcd data directory /var/lib/etcd permissions to 700
* On Flatcar Linux, /var/lib/etcd is pre-existing and Ignition
v2 doesn't overwrite the directory. Update the Container Linux
config, but add the manual chmod workaround to bootstrap for
Flatcar Linux users
* https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.4.md#v3410-2020-07-16
* https://github.com/etcd-io/etcd/pull/11798

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

@@ -140,6 +140,11 @@ systemd:
         [Install]
         WantedBy=multi-user.target
 storage:
+  directories:
+    - path: /var/lib/etcd
+      filesystem: root
+      mode: 0700
+      overwrite: true
   files:
     - path: /etc/kubernetes/kubeconfig
       filesystem: root
@@ -161,6 +166,7 @@ storage:
           mv tls/etcd/etcd-client* /etc/kubernetes/bootstrap-secrets/
           chown -R etcd:etcd /etc/ssl/etcd
           chmod -R 500 /etc/ssl/etcd
+          chmod -R 700 /var/lib/etcd
           mv auth/kubeconfig /etc/kubernetes/bootstrap-secrets/
           mv tls/k8s/* /etc/kubernetes/bootstrap-secrets/
           mkdir -p /etc/kubernetes/manifests