FYI: IPv6 needs default Docker config file.

With ipv6 enabled the older OS5 LTS kernel attempting to run a later (>27.0.1) Docker version fails with network initialization.

The "fix" here is to set `/etc/docker/daemon.json` to:
```
{
  "ip6tables": false
}
```
Any guidance on setting this at install time so it persists across reboot? I'd be happy to submit a PR.