feat: Enable seccomp profile defaulting

[christinalau0]

Reason for Change:

To use seccomp profile defaulting, you must run the kubelet with the --seccomp-default enabled for each node where you want to use it. If enabled, the kubelet will use the RuntimeDefault seccomp profile by default, which is defined by the container runtime, instead of using the Unconfined (seccomp disabled) mode. The default profiles aim to provide a strong set of security defaults while preserving the functionality of the workload.

Manually verified in the cluster (using crictl) that the Runtimedefault seccomp profile is set by default in all containers. https://kubernetes.io/blog/2021/08/25/seccomp-default/#trying-it-out

To override the default behavior, pods and containers can also manually set seccompProfile Unconfined.

Will add automated functional validation in kubernetes_test.go at a later time.

Issue Fixed:

Credit Where Due:

Does this change contain code from or inspired by another project?

• No
• Yes

If "Yes," did you notify that project's maintainers and provide attribution?

• No
• Yes

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

[christinalau0]

/azp run

[azure-pipelines]

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