Add an Installer CI job for custom-dns on GCP that is not automatically run. This job would help with testing the feature now and later to indicate when this feature is ready to be pulled out of tech-preview.

User Story:

As a (user persona), I want to be able to:

• Capability 1
• Capability 2
• Capability 3

so that I can achieve

• Outcome 1
• Outcome 2
• Outcome 3

Acceptance Criteria:

Description of criteria:

• Upstream documentation
• Point 1
• Point 2
• Point 3

(optional) Out of Scope:

Detail about what is specifically not being delivered in the story

Engineering Details:

• (optional) https://github/com/link.to.enhancement/
• (optional) https://issues.redhat.com/link.to.spike
• Engineering detail 1
• Engineering detail 2

This requires/does not require a design proposal.
This requires/does not require a feature gate.