code: private Animator preparePulseAnimation() {
          AnimatorSet animation = new AnimatorSet();
  
          Animator firstBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
                  drawable.getCircleScale(), 0.88f);
          firstBounce.setDuration(300);
          firstBounce.setInterpolator(new CycleInterpolator(1));
          Animator secondBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
                  0.75f, 0.83f);
          secondBounce.setDuration(300);
          secondBounce.setInterpolator(new CycleInterpolator(1));
          Animator thirdBounce = ObjectAnimator.ofFloat(drawable, CircularProgressDrawable.CIRCLE_SCALE_PROPERTY,
                  0.75f, 0.80f);
          thirdBounce.setDuration(300);
          thirdBounce.setInterpolator(new CycleInterpolator(1));
  
          animation.playSequentially(firstBounce, secondBounce, thirdBounce);
          return animation;
      }
docs: This animation will make a pulse effect to the inner circle
  
  @return Animation