On Attitude Available Listener
fun interface OnAttitudeAvailableListener<T : BaseRelativeGyroscopeAttitudeEstimator2<T, L1, L2>, L1 : BaseRelativeGyroscopeAttitudeEstimator2.OnAttitudeAvailableListener<T, L1, L2>, L2 : BaseRelativeGyroscopeAttitudeEstimator2.OnAccuracyChangedListener<T, L1, L2>>
Interface to notify when a new relative attitude measurement is available.