_source_policy_documents_ variable being ignored

[hudelgado]

Describe the Bug

The source_policy_documents variable is ignored since it's referencing an undefined local.source_policy_documents variable.

Expected Behavior

Final aws_s3_bucket_policy should have the override_policy_documents.

Steps to Reproduce

data "aws_iam_policy_document" "override" {
  statement {
    sid = "SidToOverride"

    actions   = ["s3:*"]
    resources = ["*"]
  }
}

module "s3_bucket_test_source_policy_documents" {
  source  = "cloudposse/s3-bucket/aws"
  version = "0.49.0"

  name                         = "test_source_policy_documents"
  acl                          = "private"
  enabled                      = true
  versioning_enabled           = false
  allow_encrypted_uploads_only = false
  allow_ssl_requests_only      = false

  block_public_acls       = false
  block_public_policy     = false
  ignore_public_acls      = false
  restrict_public_buckets = false

  source_policy_documents = [data.aws_iam_policy_document.override.json]
}

Generated plan didn't contain the override policy document.

Additional Context

Seems to be similar with #145

[hudelgado]

the local is actually defined in a different place:
https://github.com/cloudposse/terraform-aws-s3-bucket/blob/master/variables.tf#L35