### 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_
"""
    The SMS publisher is responsible for publishing the SNS message to a subscribed phone number.
    This is not directly implemented yet in LocalStack, we only save the message.
    # TODO: create an internal endpoint to retrieve SMS.
    """
    def _publish(self, context: SnsPublishContext, subscriber: SnsSubscription):
        event = self.prepare_message(context.message, subscriber)
        context.store.sms_messages.append(event)
        LOG.info(
            "Delivering SMS message to %s: %s from topic: %s",
            event["endpoint"],
            event["message_content"],
            event["topic_arn"],
        )
        
        delivery = {
            "phoneCarrier": "Mock Carrier",
            "mnc": 270,
            "priceInUSD": 0.00645,
            "smsType": "Transactional",
            "mcc": 310,
            "providerResponse": "Message has been accepted by phone carrier",
            "dwellTimeMsUntilDeviceAck": 200,
        }
        store_delivery_log(context.message, subscriber, success=True, delivery=delivery)
    def prepare_message(self, message_context: SnsMessage, subscriber: SnsSubscription) -> dict: