### 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_
num_msgs_0 = len(response_0.get("Messages", []))
        # p
        message = "This is a test message"
        message_attributes = {"attr1": {"DataType": "Number", "StringValue": "99"}}
        sns_client.publish(
            TopicArn=topic_arn,
            Message=message,
            MessageAttributes=message_attributes,
        )
        response_1 = sqs_client.receive_message(
            QueueUrl=queue_url, VisibilityTimeout=0, WaitTimeSeconds=4
        )
        snapshot.match("messages-1", response_1)
        num_msgs_1 = len(response_1["Messages"])
        assert num_msgs_1 == (num_msgs_0 + 1)
        # p
        message = "This is another test message"
        sns_client.publish(
            TopicArn=topic_arn,
            Message=message,
            MessageAttributes={"attr1": {"DataType": "Number", "StringValue": "111"}},
        )
        response_2 = sqs_client.receive_message(
            QueueUrl=queue_url, VisibilityTimeout=0, WaitTimeSeconds=4
        )
        snapshot.match("messages-2", response_2)
        num_msgs_2 = len(response_2["Messages"])
        assert num_msgs_2 == num_msgs_1
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(paths=["$..Attributes.SubscriptionPrincipal"])