create schedule adroid studio, make ads show every second as well

scheduleAd.java

public class MainActivity extends AppCompatActivity {
    private InterstitialAd interstitialAd;
    private ScheduledExecutorService scheduledExecutorService;
    private Boolean isVisible;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AdView adView = findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().build();
        adView.loadAd(adRequest);

        pripareADs();


    }

    @Override
    protected void onStart() {
        super.onStart();
        isVisible = true;
        if (scheduledExecutorService == null){
            scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
            scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
                @Override
                public void run() {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (interstitialAd.isLoaded()){
                                interstitialAd.show();
                            }else{
                                Toast.makeText(getApplicationContext(),"iklan gk uncul",Toast.LENGTH_LONG).show();
                            }
                            pripareADs();

                        }
                    });
                }
            },10,10, TimeUnit.SECONDS);
        }
    }

    private void pripareADs() {
        interstitialAd = new InterstitialAd(this);
        interstitialAd.setAdUnitId("ca-app-pub-3940256099942544/1033173712");
        interstitialAd.loadAd(new AdRequest.Builder().build());
    }

    @Override
    protected void onStop() {
        super.onStop();
        scheduledExecutorService.shutdownNow();
        scheduledExecutorService = null;
        isVisible = false;
    }
}