Animation结束后自动恢复到原状态

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final Button sendButton=(Button)findViewById(R.id.send_Button);
        final Animation animation= AnimationUtils.loadAnimation(this,R.anim.myan);
        animation.setFillAfter(true);
        animation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {
            }
            @Override
            public void onAnimationEnd(Animation animation) {
                sendButton.clearAnimation();
            }
            @Override
            public void onAnimationRepeat(Animation animation) {
            }
        });
        findViewById(R.id.animationButton).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                    sendButton.startAnimation(animation);
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_interpolator"
    android:shareInterpolator="true"
    android:duration="1000"
    >
    <alpha
        android:fromAlpha="0"
        android:toAlpha="500"></alpha>
    <scale
        android:pivotX="50%"
        android:pivotY="50%"
        android:fromYScale="100%"
        android:toYScale="120%"
        android:fromXScale="100%"
        android:toXScale="120%"></scale>
</set>