Support appArmor and seLinux options to gitaly security context

What does this MR do?

This MR adds the possibility to specify seLinuxOptions labels and appArmorProfile in gitaly deployment.

Related issues

I put this issue as related since this is somehow related to the cgroups configuration.

For systems like OpenShift, the following configuration is possible:

No need for io.kubernetes.cri-o.cgroup2-mount-hierarchy-rw annotation at the host level (or configured via a machine config)

init-cgroups init container configuration:

initContainers:
- name: init-cgroups
  securityContext:
    runAsGroup: 0
    runAsUser: 0
    seLinuxOptions:
      type: spc_t
...

gitaly container configuration:

containers:
  name: gitaly
  securityContext:
    allowPrivilegeEscalation: false
    capabilities:
      drop:
      - ALL
    runAsNonRoot: true
    runAsUser: 1000
    seLinuxOptions:
      type: spc_t
...

Therefore, adding the possibility to configure seLinuxOptions in the gitaly chart is convenient (it may serve for other purposes).

Author checklist

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Required

For anything in this list which will not be completed, please provide a reason in the MR discussion.

• Merge Request Title and Description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• MR has a green pipeline.
• Documentation created/updated.
• Tests added/updated, and test plan for scenarios not covered by automated tests.
• Equivalent MR/issue for omnibus-gitlab opened.

Reviewers checklist

• MR has a green pipeline on https://gitlab.com/gitlab-org/charts/gitlab.
• Consider downstream impact to the Operator, as per evaluating impact from changes to GitLab chart.