When downoading from sharepoint with buffer size always getting maximum 8K buffer and not as we asked

Describe the bug

When downloading file from sharepoint using graph api and set the buffer size to be downloaded only 8K ( maximum) is fetched ) instread of the given buffer size.
InputStream inputStream = graphServiceClient.drives().byDriveId(driveId).items().byDriveItemId(getDriveItemIdFromRootPath(filePath)).content().get();
byte[] buf = new byte[cloudPartSizeWhenDownloadingToLocal];
int bytesRead;
while ((bytesRead = srcInputStream.read(buf)) != -1) {
byresRead is always maximum 8K and not per demand
}

Expected behavior

The bytess returned from this method should aline with the request.

How to reproduce

see above

SDK Version

6.25.1

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

</details>


### Configuration

_No response_

### Other information

_No response_

Inizia dalla chiamata graphServiceClient.drives().byDriveId(...).content().get() e analizza come il Java InputStream restituito gestisce read(byte[]) per i download da SharePoint. Confronta le letture da 8K osservate con il contratto di Java InputStream e l'implementazione dello stream dell'SDK; il lavoro è completato quando il comportamento di buffering richiesto è corretto oppure chiaramente coperto da un test di regressione.