Revert "Remove metrics and alarm based scaling"
Revert "Remove metrics and alarm based scaling"

This reverts commit 55d260b9e878894776783f3bee8d9d3ee3f1cad9.

buildkite/elastic-ci-stack-for-aws,holmesjr/elastic-ci-stack-for-aws,holmesjr/elastic-ci-stack-for-aws