Start Game only after Interstitials is Closed


#1

I have “try again” button. If the player clicked the button, interstitial ads will appears.
After the player closed the ads, what I plan is the game will be restarted and run once again.
But currently what happen is when player clicked the “try again” button, interstitial ads appears and the game is run concurrently even if the player is still watching the ads.
I notice this because I have score timer which will add 1 score every 0.1 seconds, and after I closed the ads, the starting score already around 100+.

How can I add checking condition that when player closed the interstitial ads, the game just restarted ? (like function onAdClosed() in the Android Studio)