How to know when Shared Element Transition ends

Did you try to bind animation listener to the shared element view inside onMapSharedElements? ViewCompat.animate(view) will give you either a new or cached ViewPropertyAnimator(Compat) and then binding the animation listener should be trivial. I haven't tried it, though.

setEnterSharedElementCallback(new SharedElementCallback() {
            @Override
            public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
                super.onMapSharedElements(names, sharedElements);
                View keySharedElementView = sharedElements.get("keySharedElement");
                if(keySharedElementView != null){
                    ViewCompat.animate(keySharedElementView).setListener(new ViewPropertyAnimatorListenerAdapter(){
                        @Override
                        public void onAnimationEnd(View view) {
                            super.onAnimationEnd(view);
                        }
                    });
                }
            }
        });

What about adding Transition.Listener to the shared element transition?

 Transition sharedElementEnterTransition = getWindow().getSharedElementEnterTransition();
 sharedElementEnterTransition.addListener(new TransitionListenerAdapter() {
         @Override
          public void onTransitionEnd(android.support.transition.Transition transition) {
                    super.onTransitionEnd(transition);
           }
      });

Please try onEnterAnimationComplete() callback on your activity.

I bet this is exactly what you ere looking for.

 @Override
    public void onEnterAnimationComplete() {
        super.onEnterAnimationComplete();

    //your code 
    }