Enable sensor check for Analog PPO2 mode: Checks which may trigger a fallback warning were not activated in previous versions. Beside enabling the checks the test logic has been changed. Before the change an avarage was build automatically using the remaining both sensors if one sensor failed. The scenario that also one of the remaining sensors may be out of bounds was not covered. The new implementation allows an out of bounds detection for all sensors in parallel. In that special case the last valid value will be used until the diver takes action (Fallback warning)