### 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_
validate_subscription_attribute(
                    attribute_name=attr_name, attribute_value=attr_value, topic_arn=topic_arn
                )
        moto_response = call_moto(context)
        subscription_arn = moto_response.get("SubscriptionArn")
        store = self.get_store()
        topic_subs = store.sns_subscriptions[topic_arn] = (
            store.sns_subscriptions.get(topic_arn) or []
        )
        
        
        for existing_topic_subscription in topic_subs:
            if existing_topic_subscription.get("Endpoint") == endpoint:
                return SubscribeResponse(
                    SubscriptionArn=existing_topic_subscription["SubscriptionArn"]
                )
        subscription = {
            
            "TopicArn": topic_arn,
            "Endpoint": endpoint,
            "Protocol": protocol,
            "SubscriptionArn": subscription_arn,
            "PendingConfirmation": "true",
            "Owner": context.account_id,
            "RawMessageDelivery": "false",  
        }
        if attributes:
            subscription.update(attributes)
            if "FilterPolicy" in attributes:
                store.subscription_filter_policy[subscription_arn] = json.loads(