ROX-32636: Set allowPrivilegeEscalation for empty securityContext

[kurlov]

Description

Container.SecurityContext might be nil and allowPrivilegeEscalation should be set to true explicitly for such cases. Otherwise allowPrivilegeEscalation policy will not trigger on container without securityContext. See example in the ticket description.

User-facing documentation

• CHANGELOG.md is updated OR update is not needed
• documentation PR is created and is linked above OR is not needed

Testing and quality

• the change is production ready: the change is GA, or otherwise the functionality is gated by a feature flag
• CI results are inspected

Automated testing

• added unit tests
• added e2e tests
• added regression tests
• added compatibility tests
• modified existing tests

How I validated my change

Added unit test

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[rhacs-bot]

Images are ready for the commit at cc15c56.

To use with deploy scripts, first export MAIN_IMAGE_TAG=4.10.x-765-gcc15c56888.