Assigning RuntimeDefault AppArmor profile to pods/containers when strict security is enabled breaks on hosts w/o AppArmor

[jfroy]

The operator assigns the special RuntimeDefault AppArmor profile on pods and containers when strict security is enabled. On any hosts where AppArmor is not enabled, the pod will be rejected by kubelet's AppArmor admission handler, with the error "Cannot enforce AppArmor: AppArmor is not enabled on the host". This needs to be made configurable, as not all clusters will have AppArmor enabled on all hosts.