### 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_
from localstack.services.awslambda.lambda_utils import LAMBDA_RUNTIME_PYTHON37
from localstack.services.sns.constants import PLATFORM_ENDPOINT_MSGS_ENDPOINT
from localstack.services.sns.provider import SnsProvider
from localstack.testing.aws.util import is_aws_cloud
from localstack.utils import testutil
from localstack.utils.aws.arns import parse_arn
from localstack.utils.net import wait_for_port_closed, wait_for_port_open
from localstack.utils.strings import short_uid, to_str
from localstack.utils.sync import poll_condition, retry
from localstack.utils.testutil import check_expected_lambda_log_events_length
from .awslambda.functions import lambda_integration
from .awslambda.test_lambda import TEST_LAMBDA_LIBS, TEST_LAMBDA_PYTHON, TEST_LAMBDA_PYTHON_ECHO
LOG = logging.getLogger(__name__)
PUBLICATION_TIMEOUT = 0.500
PUBLICATION_RETRIES = 4
@pytest.fixture(autouse=True)
def sns_snapshot_transformer(snapshot):
    snapshot.add_transformer(snapshot.transform.sns_api())
    
    
    snapshot.add_transformer(
        snapshot.transform.key_value(
            "SubscriptionPrincipal",
            value_replacement="<sub-principal>",
            reference_replacement=False,
        ),
        priority=-1,
    )
@pytest.fixture
def sns_create_platform_application(sns_client):