Orientation sensor's reading invalid until device is rotated

[Florian Boucault]

OrientationSensor.reading.orientation returns an invalid value until the device is rotated.

Sample program:

OrientationSensor {
    id: orientationSensor
    active: true
    onReadingChanged: {
        print("ORIENTATION SENSOR READING CHANGED", reading.orientation)
    }
    Component.onCompleted: print("ORIENTATION SENSOR COMPLETED", orientationSensor.reading.orientation)
}

Output at startup:
qml: ORIENTATION SENSOR COMPLETED 1701602659

Output after rotating the device back and forth:
qml: ORIENTATION SENSOR READING CHANGED 4
qml: ORIENTATION SENSOR READING CHANGED 1