Why are the navigation buttons in a fixed position when the device is in landscape mode in Android 7.1.1?

You may have experienced that after updating your Xperia™ device to Android™ 7.1.1 (Nougat), the navigation buttons (Back/Home/Task) are in a fixed position. They will always appear at the same side as the charging port of the device. This is by design and is Android™ Open Source Project behaviour.