Fix: Change "empty" definition for PodSecurity Admission configuration (#12477)

Fixes a bug where `kube-apiserver` fails to start if the PodSecurity
configuration file doesn't have the `apiVersion` and `kind` keys.

Signed-off-by: Alejandro Macedo <alex.macedopereira@gmail.com>
Co-authored-by: Alejandro Macedo <alex.macedopereira@gmail.com>

roles/kubernetes/control-plane/templates/podsecurity.yaml.j2

@@ -1,6 +1,6 @@
-{% if kube_pod_security_use_default %}
 apiVersion: pod-security.admission.config.k8s.io/v1
 kind: PodSecurityConfiguration
+{% if kube_pod_security_use_default %}
 defaults:
   enforce: "{{ kube_pod_security_default_enforce }}"
   enforce-version: "{{ kube_pod_security_default_enforce_version }}"