Does not play an animation on Android

I'm trying to make an animation for an image, but the problem is that the animation is not running, does not show any errors, put my image I want to animate in a class that extends Fragment .

This is my class that extends from Fragment:

public class animacionesFrgmento extends Fragment {

    public FloatingActionButton reproductor;

    public  animacionesFrgmento(){

    }

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.activity_animaciones, container, false);
        reproductor = (FloatingActionButton) view.findViewById(R.id.floatingActionButton);
        reproductor.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                PlayAnimation(view);
            }
        });
        return view;
    }

    public void PlayAnimation(View view){

        Toast.makeText(getActivity(), "Reproduciendo animacion", Toast.LENGTH_LONG).show();
        ImageView esfera = (ImageView)view.findViewById(R.id.esfera);
        AnimatorSet animatorSet = (AnimatorSet) AnimatorInflater.loadAnimator(getActivity(), R.animator.animation_esfera);
        animatorSet.setTarget(esfera);
        animatorSet.start();

    }
}

This is my XML animation file, it's in a folder called "animator"

<?xml version="1.0" encoding="UTF-8"?>
<set android:ordering="together" xmlns:android="http://schemas.android.com/apk/res/android">

    <objectAnimator
        android:propertyName="x"
        android:duration="400"
        android:valueTo="500"/>

    <objectAnimator
        android:propertyName="y"
        android:duration="400"
        android:valueTo="500"/>

</set>

This is my file where I have my floating button and my ImageView:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <ImageView
        android:id="@+id/esfera"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="12dp"
        android:src="@drawable/esfera" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="40dp"
        android:clickable="true"
        app:srcCompat="@android:drawable/ic_media_play" />

</RelativeLayout>

  

I am printing a Toast in my method where I try to execute the   animation and the message if it is shown, but the animation does nothing,   the emulator where I run the project is an emulator with API 25