### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

I am running an SNS topic that publishes to a lambda function. The localstack code reads a type byte object from the lambda function invocation payload [here](https://github.com/localstack/localstack/blob/master/localstack/services/sns/publisher.py#L187) and then tries to dump the result into json [here](https://github.com/localstack/localstack/blob/master/localstack/services/sns/publisher.py#L863) which results in the following error:
```
sns_pub_0] l.services.sns.publisher   : Unable to run Lambda function on SNS message: Object of type bytes is not JSON serializable
```

### Expected Behavior

The payload bytes should be converted to a string before being dumped to json. The error should not be thrown.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

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

docker-compose up
(Using the standard docker-compose.yaml)

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

```
awslocal sns publish --message file://sns/message.json --topic-arn arn:aws:sns:us-east-1:000000000000:<topic_name>
```

### Environment

```markdown
- OS: macOS Ventura 13.2.1
- LocalStack: latest
```


### Anything else?

_No response_
platform_applications = []
    def factory(**kwargs):
        if "Name" not in kwargs:
            kwargs["Name"] = f"platform-app-{short_uid()}"
        response = sns_client.create_platform_application(**kwargs)
        platform_applications.append(response["PlatformApplicationArn"])
        return response
    yield factory
    for platform_application in platform_applications:
        endpoints = sns_client.list_endpoints_by_platform_application(
            PlatformApplicationArn=platform_application
        )
        for endpoint in endpoints["Endpoints"]:
            try:
                sns_client.delete_endpoint(EndpointArn=endpoint["EndpointArn"])
            except Exception as e:
                LOG.debug(
                    "Error cleaning up platform endpoint '%s' for platform app '%s': %s",
                    endpoint["EndpointArn"],
                    platform_application,
                    e,
                )
        try:
            sns_client.delete_platform_application(PlatformApplicationArn=platform_application)
        except Exception as e: