* This handler will set and clear the SCREEN_ON and SCREEN_OFF flag.
* How will it work - It will work in two scenario
* First - Listening - Whenever listening dialog will open, screen will keep ON and wait to Close the dialog that mean when listening dialog will dismiss then SCREEN_ON flag will clear.
* Second - Speaking - Whenever speaking will start, screen will keep ON and wait to Stop the speaking that mean when Speaking will stop then SCREEN_ON flag will clear.