etcd backup fails when a control plane operator is progressing in OpenShift

Issue

• The etcd backup script can fail when a control plane operator has a Progressing condition other than False, for example if a control plane node is down.

• Trying to collect an etcd backup following the documentation when a control plane node is down fails with messages like the following ones:

  Currently the kube-apiserver operator is progressing. A reliable backup requires that a rollout is not in progress. Aborting!
  

  Currently the etcd operator is progressing. A reliable backup requires that a rollout is not in progress.  Aborting!