Uploading file to s3 is always setting binary content type

Whenever I attempt to upload files to S3 using a presigned URL, I consistently encounter an issue where the correct content type is not being set, and instead, it consistently defaults to the binary type. What might be the underlying cause of this problem?

```
const {path} = await RNFS.stat(fileURI);
const files = [
{
name: 'file',
filename: fileName,
filepath: path,
filetype: fileType,
type: fileType,
},
];

const fields = {
Key: params.key,
Bucket: params[''],
Policy: params.policy,
AWSAccessKeyId: params.AWSAccessKeyId,
Signature: params.signature,
};

const response = await RNFS.uploadFiles({
toUrl: url,
files,
method: 'POST',
headers: {
Accept: 'application/json',
},
fields,
}).promise;
console.log(response);
return response;
} catch (exception) {
Logger.warn('Unable to upload to s3', exception);
return null;
}
}
```