vault-infra-kms: allow to choose KMS key region
Add back option to choose the AWS Region for the KMS key.
The KMS key for infra-stg has been created on eu-west-3 and we cannot move it to the same region as the backend buckect.
Add back option to choose the AWS Region for the KMS key.
The KMS key for infra-stg has been created on eu-west-3 and we cannot move it to the same region as the backend buckect.