### 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_
or list_item in value:
            if list_item is not None:
                wrapper = {}
                # The JSON list serialization is the only case where we aren't
                # setting a key on a dict.  We handle this by using
                # a __current__ key on a wrapper dict to serialize each
                # list item before appending it to the serialized list.
                self._serialize(wrapper, list_item, shape.member, "__current__", mime_type)
                list_obj.append(wrapper["__current__"])
    def _default_serialize(self, body: dict, value: Any, _, key: str, __):
        body[key] = value
    def _serialize_type_timestamp(
        self, body: dict, value: Any, shape: Shape, key: str, mime_type: str
    ):
        timestamp_format = (
            shape.serialization.get("timestampFormat")
            # CBOR always uses unix timestamp milliseconds
            if mime_type not in self.CBOR_TYPES
            else "unixtimestampmillis"
        )
        body[key] = self._convert_timestamp_to_str(value, timestamp_format)
    def _serialize_type_blob(
        self, body: dict, value: Union[str, bytes], _, key: str, mime_type: str
    ):
        if mime_type in self.CBOR_TYPES:
            body[key] = value
        else:
            body[key] = self._get_base64(value)
    def _prepare_additional_traits_in_r
        self, response: HttpResponse, operation_model: OperationModel
    ):
        response.headers["x-amzn-requestid"] = gen_amzn_requestid_long()
        response = super()._prepare_additional_traits_in_rresponse, operation_model)
        return response
class RestJSONResponseSerializer(BaseRestResponseSerializer, JSONResponseSerializer):
    """
    The ``RestJSONResponseSerializer`` is responsible for the serialization of responses from services with the
    ``rest-json`` protocol.
    It combines the ``BaseRestResponseSerializer`` (for the ReST specific logic) with the ``JSONResponseSerializer``
    (for the JSOn body response ser