### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When starting the transcription job in response job object is null:

<img width="1154" alt="Screenshot 2023-04-03 at 09 21 09" src="https://user-images.githubusercontent.com/454412/229447066-1671f811-da49-478d-bf24-252f30b17699.png">


### Expected Behavior

Response from the real AWS stack - job object is not null

<img width="1161" alt="Screenshot 2023-04-03 at 09 30 13" src="https://user-images.githubusercontent.com/454412/229441498-06125248-3b68-4679-8204-0163e8245db6.png">


### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

Using test containers, reproducing project can be found here:

https://github.com/kkocel/local-stack-transcribe-repro

### Environment

```markdown
- OS: macOS
- LocalStack: latest
```


### Anything else?

_No response_
http_servers = []
    def _create_http_endpoint(
        raw_message_delivery: bool = False,
    ) -> Tuple[str, str, str, HTTPServer]:
        server = HTTPServer()
        server.start()
        http_servers.append(server)
        server.expect_request("/sns-endpoint").respond_with_data(status=200)
        endpoint_url = server.url_for("/sns-endpoint")
        wait_for_port_open(endpoint_url)
        topic_arn = sns_create_topic()["TopicArn"]
        subscription = sns_subscription(TopicArn=topic_arn, Protocol="http", Endpoint=endpoint_url)
        subscription_arn = subscription["SubscriptionArn"]
        delivery_policy = {
            "healthyRetryPolicy": {