malformed policy / self reference

I was trying to provision AWS kms key using terraform, added the code which I am using. In this kms resource I need to add a AWS kinesis firehose role to access the kms key. For that in the code I added kms key as hardcorded (after provisioning). To add this role as part of the terraform apply I tried the below options

1. Used * in the Resource field key/* and got the error “malformed policy document exception”
2. Used aws_kms_key.key.arn Configuration for aws_kms_key.key may not refer to itself

resource "aws_kms_key" "key" {
  description             = var.description
  key_usage               = var.key_usage
  is_enabled              = true
  policy                  = jsonencode({
    Version = "2012-10-17",
    Id      = "key-default-1",
    Statement = [
       {
          Sid       = "Enable IAM User Permissions",
          Effect    = "Allow",
          Principal = { AWS = "*" },
          Action = [
            "kms:Create*",
            ..............
            "kms:CancelKeyDeletion",
          ],
          Resource = "*",
       },
       {
          "Sid": "Allow firehose role",
          "Effect": "Allow",
          "Principal": {
             "AWS": "arn:aws:iam::${local.account_id}:role/${var.somerole}"
            },
             "Action": [
                "kms:Encrypt",
                "kms:Decrypt",
                "kms:ReEncrypt*",
                "kms:GenerateDataKey*",
                "kms:DescribeKey"
             ],
             "Resource": "arn:aws:kms:eu-central-1:${local.account_id}:key/111-111-111"
       },
 .
 .
 .
}