There are quite a few similar topics and issues around here. Since you're not writing your own camera, I think it boils down to this:

some devices rotate the image before saving it, while others simply add the orientation tag in the photo's exif data.

I'd recommend checking the photo's exif data and looking particularly for

ExifInterface exif = new ExifInterface(SourceFileName);     //Since API Level 5
String exifOrientation = exif.getAttribute(ExifInterface.TAG_ORIENTATION);

Since the photo is displaying correctly in your app, i'm not sure where the problem is, but this should definitely set you on the right path!