How to listen the state of Smart Return Home feature?

After calling setSmartReturnToHomeEnabled, you can get GoHomeAssessment class to know the state of Smart Return Home feature. Inside GoHomeAssessment class, you can use getSmartRTHState() to know the state of return home.

• IDLE：The Smart Return Home isn't triggered. 
• COUNTING_DOWN：The Smart Return Home is triggered, the aircraft starts count down. If the user does not respond within 10 seconds. The Smart Return Home state wukk change to EXECUTED and start go home. If the user has canceled and the state will change to CANCELLED.
• EXECUTED：Smart Return Home already started. This state will not be changed until landed.
• CANCELLED：Smart Return Home is cancelled. This state will not be changed until landed.