fix(kubernetes): Don't require ImagePullPolicy when digest (#4776)

[candrews]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

Don't report BC_K8S_14/CKV_K8S_15 "Image Pull Policy should be Always" when the image has a digest.

Fixes #4776

New/Edited policies (Delete if not relevant)

BC_K8S_14/CKV_K8S_15 "Image Pull Policy should be Always" should not be reported when using a digest

Description

Per the documentation:

When the imagePullPolicy is set to Always, you ensure the latest version of the image is deployed every time the pod is started.

By specifying the digest, the same image is always used, so there is no concern about the latest version (since the the version cannot change), negating the need to always pull the image.

Fix

How does someone fix the issue in code and/or in runtime?

As documented.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[gruebel]

thanks, looks good 💪