### 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_
return endpoint_arn.rsplit("/", maxsplit=3)[1]  
def get_application_platform_arn_from_endpoint_arn(endpoint_arn: str) -> str:
    """
    Retrieve the application_platform information from the endpoint_arn to build the application platform ARN
    The format of the endpoint is:
    `arn:aws:sns:{region}:{account_id}:endpoint/{platform_type}/{application_name}/{endpoint_id}`
    :param endpoint_arn: str
    :return: application_platform_arn: str
    """
    parsed_arn = parse_arn(endpoint_arn)
    _, platform_type, app_name, _ = parsed_arn["resource"].split("/")
    base_arn = f'arn:aws:sns:{parsed_arn["region"]}:{parsed_arn["account"]}'
    return f"{base_arn}:app/{platform_type}/{app_name}"
def get_attributes_for_application_endpoint(endpoint_arn: str) -> Tuple[Dict, Dict]:
    """
    Retrieve the attributes necessary to send a message directly to the platform (credentials and token)
    :param endpoint_arn:
    :return:
    """
    sns_client = aws_stack.connect_to_service("sns")
    
    endpoint_attributes = sns_client.get_endpoint_attributes(EndpointArn=endpoint_arn)
    app_platform_arn = get_application_platform_arn_from_endpoint_arn(endpoint_arn)
    app = sns_client.get_platform_application_attributes(PlatformApplicationArn=app_platform_arn)
    return app.get("Attributes", {}), endpoint_attributes.get("Attributes", {})
def send_message_to_gcm(