### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When you publish a message to SNS without a *body* (e.g. only attributes) it succeeds.

### Expected Behavior

Trying to publish a message without a *body* should fail (at least it does when trying to do this in AWS)

### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

using Java testcontainers...

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

```bash
#!/bin/sh
 
queue_arn=$(awslocal sqs create-queue --queue-name $QUEUE_NAME --output text)
echo "Queue ARN: $queue_arn"

topic_arn=$(awslocal sns create-topic --name $TOPIC_NAME --output text)
echo "Topic ARN: $topic_arn"

subscription_arn=$(awslocal sns subscribe \
    --attributes RawMessageDelivery=true \
    --topic-arn "$topic_arn" \
    --protocol sqs \
    --notification-endpoint "$queue_arn" \
    --output text)
echo "Subscription ARN: $subscription_arn" 
```


### Environment

```markdown
- OS: OSX 11.5.2
- LocalStack: 0.13.0
- Docker Desktop: v20.10.8
```


### Anything else?

_No response_
json.loads(json.loads(result["Messages"][0]["Body"])["Message"][0])["message"],
                "test_redrive_policy",
            )
        retry(receive_dlq, retries=7, sleep=2.5)
    def test_redrive_policy_lambda_subscription(self):
        self.unsubscribe_all_from_sns()
        lambda_name = "test-%s" % short_uid()
        lambda_arn = aws_stack.lambda_function_arn(lambda_name)
        testutil.create_lambda_function(
            func_name=lambda_name,
            libs=TEST_LAMBDA_LIBS,
            handler_file=TEST_LAMBDA_PYTHON,
            runtime=LAMBDA_RUNTIME_PYTHON36,
        )
        subscription = self.sns_client.subscribe(
            TopicArn=self.topic_arn, Protocol="lambda", Endpoint=lambda_arn
        )
        self.sns_client.set_subscription_attributes(
            SubscriptionArn=subscription["SubscriptionArn"],
            AttributeName="RedrivePolicy",
            AttributeValue=json.dumps(
                {"deadLetterTargetArn": aws_stack.sqs_queue_arn(TEST_QUEUE_DLQ_NAME)}
            ),
        )
        testutil.delete_lambda_function(lambda_name)
        self.sns_client.publish(
            TopicArn=self.topic_arn,
            Message=json.dumps({"message": "test_redrive_policy"}),
        )
        def receive_dlq():