K8SSAND-1880 ⁃ Do not mount encryption-cred-storage

[burmanm]

What is missing?
The encryption-cred-storage is an old way to create internode encryption CAs. We don't usually need that and there's better ways to do it with cert-manager, yet we always add these mounts and create the CAs.

We should improve the situation and only create the mount if needed (if that certain hardcoded path is used or existing cluster has it) to the StatefulSet.

Why do we need it?
This also helps in the migration process.

Environment

• Cass Operator version:

  Insert image tag or Git SHA here

Anything else we need to know?:

┆Issue is synchronized with this Jira Task by Unito
┆Issue Number: K8SSAND-1880
┆Priority: Medium
┆Link To Issue: https://k8ssandra.atlassian.net/browse/K8SSAND-1880

[jsanda]

there's better ways to do it with cert-manager

Am I correct in thinking that cass-operator will not do this and it will instead be up to the user?