Update templates/aws-stack.yml
Update templates/aws-stack.yml

Co-authored-by: Paul Annesley <a027184a55211cd23e3f3094f1fdc728df5e0500@annesley.cc>
holmesjr/elastic-ci-stack-for-aws,buildkite/elastic-ci-stack-for-aws,holmesjr/elastic-ci-stack-for-aws