Etcd autconf should also check for metrics on 2381 port

[sebastien-prudhomme]

Currently Etcd autoconf is looking for Prometheus metrics on port 2379.

It seems that most of Kubernetes distros are using port 2381, which is the case for clusters build with kubeadm and also the case for my clusters.

Is it possible to add that port in: https://github.com/DataDog/integrations-core/blob/b4d0d18d7c266def7fe9d8019f98e46400fa9648/etcd/datadog_checks/etcd/data/auto_conf.yaml#L514

[sebastien-prudhomme]

Finally found away to do it just by following the doc: https://docs.datadoghq.com/containers/kubernetes/control_plane/?tab=datadogoperator#etcd