Update cluster health check command for newer etcd (#18392)

* Update cluster health check command for newer etcd

Existing docs assume the older (v3.2) etcdctl `health-check` command but with a 3.4.3 cluster (which is what kubeadm creates in the static manifest now), that subcommand is no longer supported and returns 404 errors like:
```
root@etcd-1:~# docker run --rm -it --net host -v /etc/kubernetes:/etc/kubernetes quay.io/coreos/etcd:${ETCD_TAG} etcdctl --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --ca-file /etc/kubernetes/pki/etcd/ca.crt --endpoints https://10.170.68.181:2379 cluster-health
cluster may be unhealthy: failed to list members
Error:  unexpected status code 404
```

* PR review changes

Author: ericsmalling

content/en/docs/setup/production-environment/tools/kubeadm/setup-ha-etcd-with-kubeadm.md

@@ -251,15 +251,17 @@ this example.
     ```sh
     docker run --rm -it \
     --net host \
-    -v /etc/kubernetes:/etc/kubernetes quay.io/coreos/etcd:${ETCD_TAG} etcdctl \
-    --cert-file /etc/kubernetes/pki/etcd/peer.crt \
-    --key-file /etc/kubernetes/pki/etcd/peer.key \
-    --ca-file /etc/kubernetes/pki/etcd/ca.crt \
-    --endpoints https://${HOST0}:2379 cluster-health
+    -v /etc/kubernetes:/etc/kubernetes k8s.gcr.io/etcd:${ETCD_TAG} etcdctl \
+    --cert /etc/kubernetes/pki/etcd/peer.crt \
+    --key /etc/kubernetes/pki/etcd/peer.key \
+    --cacert /etc/kubernetes/pki/etcd/ca.crt \
+    --endpoints https://${HOST0}:2379 endpoint health --cluster
     ...
-    cluster is healthy
+    https://[HOST0 IP]:2379 is healthy: successfully committed proposal: took = 16.283339ms
+    https://[HOST1 IP]:2379 is healthy: successfully committed proposal: took = 19.44402ms
+    https://[HOST2 IP]:2379 is healthy: successfully committed proposal: took = 35.926451ms
     ```
-    - Set `${ETCD_TAG}` to the version tag of your etcd image. For example `v3.2.24`.
+    - Set `${ETCD_TAG}` to the version tag of your etcd image. For example `3.4.3-0`. To see the etcd image and tag that kubeadm uses execute `kubeadm config images list --kubernetes-version ${K8S_VERSION}`, where `${K8S_VERSION}` is for example `v1.17.0`
     - Set `${HOST0}`to the IP address of the host you are testing.
 
 {{% /capture %}}