When you create a Lambda permission you send the __statement id__ as mandatory parameter.

https://docs.aws.amazon.com/lambda/latest/dg/API_AddPermission.html#API_AddPermission_RequestSyntax

However this id is generated by a random value. 

https://github.com/localstack/localstack/blob/b3917bf248b77ced8ef80a3d5c0561960066db5d/localstack/services/awslambda/lambda_api.py#L927

Due to this problem, the tools like Terraform or Ansible fail when it has to be retrieved to check the existence of this element.

If you agree I could make a PR with the fix and its test.
""" If LAMBDA_FALLBACK_URL is configured, forward the invocation of this non-existing
        Lambda to the configured URL. """
    if not config.LAMBDA_FALLBACK_URL:
        return None
    if config.LAMBDA_FALLBACK_URL.startswith('dynamodb://'):
        table_name = urlparse(config.LAMBDA_FALLBACK_URL.replace('dynamodb://', 'http://')).netloc
        dynamodb = aws_stack.connect_to_service('dynamodb')
        item = {
            'id': {'S': short_uid()},
            'timestamp': {'N': str(now_utc())},