### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Initiating a multipart S3 upload to LocalStack returns an XML document with a root element CreateMultipartUploadOutput. This causes an error in the ex_aws_s3 library I'm using. We've used the combination of LocalStack + ex_aws_s3 successfully for a few years and the error started occurring a few days ago.

### Expected Behavior

The element should be called InitiateMultipartUploadResult.

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

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

    docker run -p 4566:4566 localstack/localstack

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

    aws --debug --endpoint-url=http://localhost:4566 s3api create-multipart-upload --bucket my-bucket --key 'multipart/01'


### Environment

```markdown
- OS: Ubuntu 20.04.5 LTS
- LocalStack: latest
```


### Anything else?

S3 docs specifying InitiateMultipartUploadResult:
https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateMultipartUpload.html

Reference in official AWS Java client:
https://github.com/aws/aws-sdk-java/blob/ef22b94750d4c155d74b09012b3be5d9d98bbd33/aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/transform/XmlResponsesSaxParser.java#L1865

Where our particular error gets raised in ex_aws_s3:
https://github.com/ex-aws/ex_aws_s3/blob/7e12f2b0578b2620c047d2e44c40a6de8773584a/lib/ex_aws/s3/parsers.ex#L78
routing_rules = website_config.get("RoutingRules", [])
        if len(routing_rules) == 0:
            raise MalformedXML()
        if len(routing_rules) > 50:
            raise "Something?"
        for routing_rule in routing_rules:
            redirect = routing_rule.get("Redirect", {})
            
            
            
            if "ReplaceKeyPrefixWith" in redirect and "ReplaceKeyWith" in redirect:
                raise InvalidRequest(
                    "You can only define ReplaceKeyPrefix or ReplaceKey but not both."
                )
            if "Condition" in routing_rule and not routing_rule.get("Condition", {}):
                raise InvalidRequest(
                    "Condition cannot be empty. To redirect all requests without a condition, the condition element shouldn't be present."
                )
            if (protocol := redirect.get("Protocol")) and protocol not in ("http", "https"):
                raise InvalidRequest(
                    "Invalid protocol, protocol can be http or https. If not defined the protocol will be selected automatically."
                )
def is_object_expired(
    context: RequestContext, bucket: BucketName, key: ObjectKey, version_id: str = None
) -> bool:
    moto_backend = get_moto_s3_backend(context)
    moto_bucket = get_bucket_from_moto(moto_backend, bucket)
    key_object = get_key_from_moto_bucket(moto_bucket, key, version_id=version_id)
    return is_key_expired(key_object=key_object)
def _create_redirect_for_post_request(