fix: Fixed various issues in the CRD structure

[sbernauer]

Description

Part of stackabletech/issues#469

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] Helm chart can be installed and deployed operator works
- [ ] Integration tests passed (for non trivial changes)
- [ ] Changes need to be "offline" compatible

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added

[maltesander]

LGTM!

[lfrancke]

Is this a CRD change? Breaking?

[maltesander]

Its breaking in terms of removing a bad default (empty string) which would not have worked anyways if left out since the pods would not be able to read from / mount a secret with an empty name...
@sbernauer and i decided this is basically non breaking in terms of functionality and crd adaptation (since leaving it out would not work) and skip this in the arch meeting.

[sbernauer]

Agreed!

[lfrancke]

I probably need to ask better questions.
What I'm wondering is if people will need to change their custom resources as a result of this.

[maltesander]

If you did not specify the optional value and used the bad default, the deployed pods will never start.
So i would assume everyone that is using it has a value set here.