gyro calibration: add median filter to motion detection
gyro calibration: add median filter to motion detection

The bmi088 has a bit more noise and tends to trigger it.
This improves reobustness against noise, and increases the threshold
slightly.

acfloria/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,krbeverx/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,PX4/Firmware,PX4/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware,krbeverx/Firmware