fix: Fixed policy name when create_role is false (#371)

iam.tf

@@ -12,7 +12,7 @@ locals {
   #   for #83 that will allow one to import resources without receiving an error from coalesce.
   # @see https://github.com/terraform-aws-modules/terraform-aws-lambda/issues/83
   role_name   = local.create_role ? coalesce(var.role_name, var.function_name, "*") : null
-  policy_name = coalesce(var.policy_name, local.role_name)
+  policy_name = coalesce(var.policy_name, local.role_name, "*")
 
   # IAM Role trusted entities is a list of any (allow strings (services) and maps (type+identifiers))
   trusted_entities_services = distinct(compact(concat(