### 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_
hape.name}: '{xmlnode}' cannot be parsed to {shape.type_name}."
            ) from e
    def _serialize_type_structure(
        self, xmlnode: ETree.Element, params: dict, shape: StructureShape, name: str, mime_type
    ) -> None:
        structure_node = ETree.SubElement(xmlnode, name)
        if "xmlNamespace" in shape.serialization:
            namespace_metadata = shape.serialization["xmlNamespace"]
            attribute_name = "xmlns"
            if namespace_metadata.get("prefix"):
                attribute_name += ":%s" % namespace_metadata["prefix"]
            structure_node.attrib[attribute_name] = namespace_metadata["uri"]
        for key, value in params.items():
            if value is None:
                # Don't serialize any param whose value is None.
                continue
            try:
                member_shape = shape.members[key]
            except KeyError:
                LOG.warning(
                    "Response object %s contains a member which is not specified: %s",
                    shape.name,
                    key,
                )
                continue
            member_name = member_shape.serialization.get("name", key)
            # We need to special case member shapes that are marked as an xmlAttribute.
            # Rather than serializing into an XML child node, we instead serialize the shape to
            # an XML attribute of the *current* node.
            if member_shape.serialization.get("xmlAttribute"):
                # xmlAttributes must have a serialization name.
                xml_attribute_name = member_shape.serialization["name"]
                structure_node.attrib[xml_attribute_name] = value
                continue
            self._serialize(member_shape, value, structure_node, member_name, mime_type)
    def _serialize_type_list(
        self, xmlnode: ETree.Element, params: list, shape: ListShape, name: str, mime_type: str
    ) -> None:
        if params is None:
            # Don't serialize