I created a CloudFormation stack using the template below via Boto3 Python method `cf_client.create_stack(StackName="test")`; however, when I attempt to call `s3_client.get_bucket_policy(Bucket="my-bucket")` I receive a `NoSuchBucketPolicy ... The bucket policy does not exist` error. 

```yaml
---
AWSTemplateFormatVersion: "2010-09-09"
Description: A sample template

Resources:
  TestBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: my-bucket
      AccessControl: PublicRead
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256

  TestBucketPolicy:
    Type: AWS::S3::BucketPolicy
    Properties:
      Bucket:
        Ref: TestBucket
      PolicyDocument:
        Id: TestBucketPolicy
        Statement:
          - Action:
              - "s3:GetObject"
            Effect: "Allow"
            Resource:
              Fn::Join:
                - ""
                - - "arn:aws:s3:::"
                  - Ref: TestBucket
                  - "/*"
            Principal: "*"
            Condition:
              StringLike:
                aws:Referer:
                  - "http://www.example.com/*"
                  - "http://example.com/*"
```

Is this something that's supported? 

Thanks in advance. 
try:
        client = aws_stack.connect_to_service('cloudformation')
        stack = client.describe_stacks(StackName=stack_name)['Stacks']
    except Exception:
        return None
    stack = stack and stack[0]
    if not stack:
        return None
    result = [p['ParameterValue'] for p in stack['Parameters'] if p['ParameterKey'] == parameter]
    return (result or [None])[0]
def update_resource(resource_id, resources, stack_name):
    resource = resources[resource_id]
    resource_type = get_resource_type(resource)
    if resource_type not in UPDATEABLE_RESOURCES:
        LOG.warning('Unable to update resource type "%s", id "%s"' % (resource_type, resource_id))
        return
    LOG.info('Updating resource %s of type %s' % (resource_id, resource_type))
    props = resource['Properties']
    if resource_type == 'Lambda::Function':
        client = aws_stack.connect_to_service('lambda')
        keys = ('FunctionName', 'Role', 'Handler', 'Description', 'Timeout', 'MemorySize', 'Environment', 'Runtime')
        update_props = dict([(k, props[k]) for k in keys if k in props])
        update_props = resolve_refs_recursively(stack_name, update_props, resources)
        if 'Code' in props:
            client.update_function_code(FunctionName=props['FunctionName'], **props['Code'])
        return client.update_function_configuration(**update_props)
    if resource_type == 'ApiGateway::Method':
        client = aws_stack.connect_to_service('apigateway')
        integration = props.get('Integration')