### 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_
rn self._get_base64(json.dumps(value, separators=(",", ":")))
        else:
            return value
    def _partition_members(self, parameters: dict, shape: Optional[Shape]) -> Tuple[dict, dict]:
        """Separates the top-level keys in the given parameters dict into header- and payload-located params."""
        if not isinstance(shape, StructureShape):
            # If the shape isn't a structure, we default to the whole response being parsed in the body.
            # Non-payload members are only loaded in the top-level hierarchy and those are always structures.
            return {}, parameters
        header_params = {}
        payload_params = {}
        shape_members = shape.members
        for name in shape_members:
            member_shape = shape_members[name]
            if name not in parameters:
                continue
            ")
            :
                header_params[name] = parameters[name]
            else:
                payload_params[name] = parameters[name]
        return header_params, payload_params
class RestXMLResponseSerializer(BaseRestResponseSerializer, BaseXMLResponseSerializer):
    """
    The ``RestXMLResponseSerializer`` is responsible for the serialization of responses from services with the
    ``rest-xml`` protocol.
    It combines the ``BaseRestResponseSerializer`` (for the ReST specific logic) with the ``BaseXMLResponseSerializer``
    (for the XML body response serialization).
    """
    pass
class QueryResponseSerializer(BaseXMLResponseSerializer):
    """
    The ``QueryResponseSerializer`` is responsible for the serialization of responses from services which use the
    ``query`` protocol. The responses of these services also use XML. It is basically a subset of the features, since it
    does not allow any payload or location traits.
    """
    def _serialize_r
        self,
        parameters: dict,
        response: HttpResponse,
        shape: Optional[Shape],
        shape_members: dict,
        operatio