Fixes wrong region on KMS key def'n

base/account_standards/iam.tf

@@ -79,7 +79,7 @@ data "aws_iam_policy_document" "default_instance_policy_s3_binaries_doc" {
     sid       = "UseTheKey"
     effect    = "Allow"
     resources = [
-      "arn:${var.aws_partition}:kms:us-gov-east-1:${var.common_services_account}:${var.binaries_key}"
+      "arn:${var.aws_partition}:kms:${var.aws_region}:${var.common_services_account}:${var.binaries_key}"
     ]
     actions = [
       "kms:Decrypt",