updatecli: use shared policy

[v1v]

What does this pull request do?

Use a shared updatecli policy. The exact configuration is used in different GitHub repositories.

I ran https://github.com/elastic/apm-agent-ruby/actions/runs/9806254252, and PR was created:

• [Automation] Update JSON specs #1443 vs [Automation] Update JSON specs #1468

Why is it important?

Avoid duplicated configuration

Checklist

• I have signed the Contributor License Agreement.
• My code follows the style guidelines of this project (See .rubocop.yml)
• I have rebased my changes on top of the latest main branch

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

• I have made corresponding changes to the documentation
• I have updated CHANGELOG.asciidoc
• I have updated supported-technologies.asciidoc
• Added an API method or config option? Document in which version this will be introduced

Related issues