### 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_
n the operation model (if defined), otherwise 200.
        :param operation_model: ault HTTP status code
        :param mime_type: Mime type which should be used to encode the payload
        :return: boiTP response
        """
        return HttpR, 200))
    def _get_ headers: Optional[Dict | Headers]) -> str:
        """
        Extracts the accepted mom the request headers and returns a matchted mime type for the
        seriafault mime type of the service if there is no match.
        :param headers: to extract the "Accept" header from
        :return: preferred mime type to be used by the serializer (if it is not accepted by the client,
                 an error is logged)
        """
        accept_header = None
        if headers and "Accept" in headers and not headers.get("Accept") == "*/*":
            accept_header = headers.get("Accept")
        elif headers and headers.get("Content-Type"):
            # If there is no specific Accept header given, we use the given Content-Type as a fallback.
            # i.e. if the request content was JSON encoded and the client doesn't send a specific an Accept header, the
            # serializer should prefer JSON encoding.
            content_type = headers.get("Content-Type")
            LOG.debug(
                "No accept header given. Using request's Content-Type (%s) as preferred response Content-Type.",
                content_type,
            )
            accept_header = content_type + ", */*"
        mime_accept: MIMEAccept = parse_accept_header(accept_header, MIMEAccept)
        mime_type = mime_accept.best_match(self.SUPPORTED_MIME_TYPES)
        if not mime_type:
            # There is no match between the supported mime types and the requested one(s)
            mime_type = self.SUPPORTED_MIME_TYPES[0]
            LOG.debug(
                "Determined accept type (%s) is not supported by this serializer. Using default of this serializer: %s",
                accept_header,
                mime_type,