### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When multi uploading a file for Glacier Instant Retrieval, the operation fails at Complete stage with a message claiming storage class not supported.

### Expected Behavior

It works with real S3.

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

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

localstack start

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

 ```golang
	b, p := parse1(path)
	cmuI := &awsS3.CreateMultipartUploadInput{
		Bucket:       b,
		Key:          p,
		StorageClass: mtypes.StorageClassGlacierIr,
	}
_, err := client.CreateMultipartUpload(context.Background(), cmuI)

```
and process the upload of the part and then complete

### Environment

```markdown
- OS: Ubuntu 20.04
- LocalStack: pro latest
```


### Anything else?

_No response_
self, context: RequestContext, bucket: BucketName, body: IO[Body] = None
    ) -> PostResponse:
        
        
        
        validate_post_policy(context.request.form)
        
        
        
        try:
            response: PostResponse = call_moto(context=context)
        except ServiceException as e:
            if e.status_code == 303:
                
                response = PostResponse(StatusCode=e.status_code)
            else:
                raise e
        key_name = context.request.form.get("key")
        if "${filename}" in key_name:
            key_name = key_name.replace("${filename}", context.request.files["file"].filename)
        moto_backend = get_moto_s3_backend(context)
        key = get_key_from_moto_bucket(
            get_bucket_from_moto(moto_backend, bucket=bucket), key=key_name
        )