Use EE_LICENSE var in cloud activation scenario

What does this MR do and why?

• Use EE_LICENSE var during instance setup for cloud_activation job, so that Gitlab instance has a valid license when the license usage data is seeded.

Screenshots or screen recordings

Pipeline result - https://gitlab.com/gitlab-org/gitlab-qa/-/jobs/2717941327 ✅

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.