OSDOCS-3520: RN for GCP Marketplace support

[mjpytlak]

Version(s): 4.12

Issue: This PR is the release note for osdocs-3520.

Link to docs preview: Google Marketplace offering

QE review:

• [ ] QE has approved this change.

[ocpdocs-previewbot]

🤖 Updated build preview is available at: https://51706--docspreview.netlify.app

Build log: https://circleci.com/gh/ocpdocs-previewbot/openshift-docs/2830

[mjpytlak]

@jianli-wei Release note for GCP Marketplace is ready for review. PTAL.

@dmesser I used the same language from the KCS [1]. OK with using the same language in the release notes?

[1] https://access.redhat.com/articles/6976804

[jianli-wei]

/label qe-approved

[mjpytlak]

Confirmed in Slack that Daniel Messer is good with using language from the KCS.