* Fix inconsistent handling of admission plugin list

* Adjust hardening doc with the normalized admission plugin list

* Add pre-check for admission plugins format change

* Ignore checking admission plugins value when variable is not defined

When trying to add a hardening CI job by copying configuration from
hardening.md, yamllint CI job deleted invalid format.
This fixes it for maintaining the CI job.

* feat: add kubelet systemd service hardening option

* refactor: move variable name to kubelet_secure_addresses

Co-authored-by: Cristian Calin <6627509+cristicalin@users.noreply.github.com>

* docs: add diagram about kubelet_secure_addresses variable

Co-authored-by: Cristian Calin <6627509+cristicalin@users.noreply.github.com>

* Add the option to enable default Pod Security Configuration

Enable Pod Security in all namespaces by default with the option to
exempt some namespaces. Without the change only namespaces explicitly
configured will receive the admission plugin treatment.

* Fix the PR according to code review comments

* Revert the latest changes

- leave the empty file when kube_pod_security_use_default, but add comment explaining the empty file
- don't attempt magic at conditionally adding PodSecurity to kube_apiserver_admission_plugins_needs_configuration

* docs(hardening): add SeccompDefault admission plugin to kubelet feature gates

* fix(kubelet-config): enable config through kubelet_feature_gates

* feat(kubelet): add kubelet_seccomp_default variable

* feat: make kubernetes owner parametrized

* docs: update hardening guide with configuration for CIS 1.1.19

* fix: set etcd data directory permissions to be compliant to CIS 1.1.12