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/fedora-coreos/kubernetes/fcc/controller.yaml

@@ -128,6 +128,8 @@ systemd:
         ExecStartPost=-/usr/bin/podman stop bootstrap
 storage:
   directories:
+    - path: /var/lib/etcd
+      mode: 0700
     - path: /etc/kubernetes
     - path: /opt/bootstrap
   files: