### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Sending a message with body:
`"&quot;&quot;"`
is received on the consumer side with body:
`""""`

### Expected Behavior

Sending a message with body:
"&quot;&quot;"
is received on the consumer side with body:
"&quot;&quot;"

### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

Running localstack in docker desktop on Mac using helm chart

https://localstack.github.io/helm-charts
version 0.3.7
Image version: 0.14.3

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)



### Environment

```markdown
- OS: macOS Monterey
- LocalStack: 0.14.3
```


### Anything else?

_No response_
r_name in event:
                        shape
                        event_member_name = member_name
                        break
                if event_member_shape is None:
                     shape for serialization.")
                # serialize the part of the response for the event
                self._serialize_r
                    event.get(event_member_name),
                    serialized_event_response,
                    event_member_shape,
                    rs if event_member_shape is not None else None,
                    operation_model,
                    mime_type,
                )
                # execute additional response traits (might be modifying the response)
                serialized_event_response = self._prepare_additional_traits_in_r
                    serialized_event_response, operation_model
                )
                # encode the event and yield it
                yield _event_payload(
                    event_type=event_member_name, content=serialized_event_response.data
                )
        return HttpR
            response=event_stream_serializer(),
            , 200),
        )
    def _encode_event_payload(
        self,
        event_type: str,
        content: Union[str, bytes] = "",
        error_code: Optional[str] = None,
        error_message: Optional[str] = None,
    ) -> bytes:
        """
        Encodes the given event payload according to AWS specific binary event encoding.
        A specification of the format can be found in the AWS docs:
        https://docs.aws.amazon.com/AmazonS3/latest/API/RESTSelectObjectAppendix.html
        :param content: string or bytes of the event payload
        :param event_type: type of the event. Usually the name of the event shape 
                            "initial-response".
        :param error_code: Optional. Error code if the payload represents an error.
        :param error_message: Optional. Error message if the payload represents an error.
    