yes, the docs are valid for 1.x
the x/crypto/acme/autocert package is configured to write certificates to /data/golang-autocert. Make sure you mount /data as a rw volume.
$ ls /data/golang-autocert/
acme_account+key cloud.drone.io
certificates in /etc/ssl come from the alpine ssl certificate package which is installed with apk add ca-certificates. I cannot speak to the CA or email address, however, if you have specific questions I recommend reaching out to the package maintainer.
maybe the default kubernetes environment variables are causing some sort of conflict? we have seen this before where kubernetes {SERVICE}_HOST and {SERVICE}_PROTO variables cause problems depending on how things are named. https://kubernetes.io/docs/concepts/containers/container-environment-variables/#cluster-information
you would be able to rule out configuration issues by looking for the following entry in your logs and checking the host, address, port and protocol
{
"acme": true,
"host": "cloud.drone.io",
"level": "info",
"msg": "starting the http server",
"port": ":443",
"proto": "https",
"time": "2019-07-15T03:02:22Z",
"url": "https://cloud.drone.io"
}