kms: allow user to pass separate kms keys for s3 and db#165

Jeff McCune (jeffmccune) wants to merge 3 commits into

braintrustdata:mainbraintrustdata/terraform-aws-braintrust-data-plane:mainfrom

jeffmccune:v3.1.0-tr1-contribjeffmccune/terraform-aws-braintrust-data-plane:v3.1.0-tr1-contribCopy head branch name to clipboard