fix: Invalid termination_grace_period default in ProbeBuilder

[sbernauer]

Description

Noticed in https://testing.stackable.tech/job/superset-operator-it-weekly/69

create Pod superset-node-default-0 in StatefulSet superset-node-default failed error: Pod "superset-node-default-0" is invalid: [spec.containers[0].livenessProbe.terminationGracePeriodSeconds: Invalid value: 0: must be greater than 0, spec.containers[0].readinessProbe.terminationGracePeriodSeconds: Invalid value: 0: must be greater than 0, spec.containers[0].readinessProbe.terminationGracePeriodSeconds: Invalid value: 0: must not be set for readinessProbes, spec.containers[0].startupProbe.terminationGracePeriodSeconds: Invalid value: 0: must be greater than 0]

Also copy some docs from k8s docs

Definition of Done Checklist

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Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• 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]

Minor stuff, LGTM otherwise!

[sbernauer]

Thanks! Somehow my VSCode behavior on quotes changed....

[maltesander]

LGTM!