No way to force a certain orientation angle

[rakuco]

Motion sensor APIs like Accelerometer and Gyroscope support different coordinate systems as described in https://w3c.github.io/accelerometer/#reference-frame

Testing this in WPT requires a programmatic way to change the value reported by screen.orientation.angle, as the sensor readings only differ between the two coordinate systems if the angle is not 0.

At the moment, the best we can do is attempt to call screen.orientation.lock() with different values and at the end check if the angle's changed to a value we want, which probably won't work in most platforms we test regularly.