App Inventor Android Studio - Flip Card Effect

[Luis Borges]

I'm trying to make an effect on two images, as if it were a flip card annimation. Image 1 = "botaoiniciar" and Image 2 = "botaosair". At the moment when I click on the initial, it turns the second, but then it gets stuck on the second image and I would like it to come back. I am using the following code. I thank you for your attention.

final ImageView botaoiniciar = (ImageView) findViewById(R.id.botaoiniciar);

   botaoiniciar.setOnClickListener(new View.OnClickListener() {
       [USER=1021285]@override[/USER]
       public void onClick(View view) {
           final ObjectAnimator oa1 = ObjectAnimator.ofFloat(botaoiniciar, "scaleX", 1f, 0f);
           final ObjectAnimator oa2 = ObjectAnimator.ofFloat(botaoiniciar, "scaleX", 0f, 1f);
           oa1.setInterpolator(new DecelerateInterpolator());
           oa2.setInterpolator(new AccelerateDecelerateInterpolator());
           oa1.addListener(new AnimatorListenerAdapter() {
               [USER=1021285]@override[/USER]
               public void onAnimationEnd(Animator animation) {
                   super.onAnimationEnd(animation);
                   botaoiniciar.setImageResource(R.drawable.botaosair);
                   oa2.start();
               }
           });
           oa1.start();
       }
   });