uploadFile doesn't work work with non-English text comments

[Ninjaman494]

I'm using this api in my Android app to send a slack message containing a screenshot and some diagnostic text, which is in the initial comment. Everything works great when the text is in English, but with non-English characters the comments show up as question marks in Slack. My guess is that the text is being encoded incorrectly.

Here's the call I make:

webApiClient.uploadFile(feedback.screenshotFile, "screenshot", "가다" , channel);

Strangely, this problem doesn't occur with postMessage, the text is encoded correctly and is shown correctly in Slack.

Thanks in advance!