### 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_
grants = []
    def _create_grant(**kwargs):
        
        
        GRANTEE_PRINCIPAL_ARN = (
            "arn:aws:kms:eu-central-1:123456789876:key/198a5a78-52c3-489f-ac70-b06a4d11027a"
        )
        if "Operations" not in kwargs:
            kwargs["Operations"] = ["Decrypt", "Encrypt"]
        if "GranteePrincipal" not in kwargs:
            kwargs["GranteePrincipal"] = GRANTEE_PRINCIPAL_ARN
        if "KeyId" not in kwargs:
            kwargs["KeyId"] = kms_create_key()["KeyId"]
        grant_id = kms_client.create_grant(**kwargs)["GrantId"]
        grants.append((grant_id, kwargs["KeyId"]))
        return grant_id, kwargs["KeyId"]
    yield _create_grant
    for grant_id, key_id in grants:
        try:
            kms_client.retire_grant(GrantId=grant_id, KeyId=key_id)
        except Exception as e:
            LOG.debug("error cleaning up KMS grant %s: %s", grant_id, e)
@pytest.fixture
def kms_key(kms_create_key):