Conditionally create a service linked policy

I’m hitting an idempotency issue:

My initial gut re-action is to use count to make this conditional like so:

data "aws_iam_role" "service_linked_role" {
  name = "AWSServiceRoleForAmazonElasticsearchService"

resource "aws_iam_service_linked_role" "es" {
  aws_service_name = ""

  count = if != "" ? 0 : 1

But, hashicorp has decided they don’t want to support this:

The next option I can think of, is move this out of my modules/aws-elasticsearch up into my, but it belongs with the elasticsearch code, imho.

Am I stuck making a modules/aws-elasticsearch-setup module which only gets called once??? There has to be a better way!

edit: bug filed