Add health checks for the newly deployed review apps in verify_deploy

Context

In gitlab-org/quality/engineering-productivity/team!36 (merged), we added more details on how the review apps get setup at the networking level.

This context can be encoded in a set of health checks to do after we deploy a review app.

Goal

Transform the docs we have in gitlab-org/quality/engineering-productivity/team!36 (merged) in code, specifically health checks, for verify_deploy