The rotation of the image is normal, as the data is raw camera data and the camera is not aware of screen rotation. You don't need to care about the rotation if you only need to get text from zxing. QRCode is designed that rotation doesn't affect its decoding.
If you want to display the detected quadrangle, you need to first get the coordinates from zxing and then apply the rotation from inputFrame.cameraParameters().imageOrientation(screenRotation).