Update review APP to use `ee` subdomain

Review apps are currently using the gitlab-review.app domain for EE, and ce.gitlab-review.app for CE.

Migrate the EE review apps to use ee.gitlab-review.app by doing the following:

• Change REVIEW_APPS_DOMAIN value in the CI/CD variabls under settings in the EE project

• Update the tls-cert secret to use the appropriate key from https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/5207

• Existing reviews need to be stopped, or recreated to use the new domain