问AnimatedVectorDrawable抛出UnsupportedOperationException

EN

<set xmlns:android="http://schemas.android.com/apk/res/android">
<objectAnimator
        android:duration="1000"
        android:propertyName="downToUp"
        android:valueFrom="M7.41,7.84L12,12.42l4.59,-4.58L18,9.25l-6,6 -6,-6z"
        android:valueTo="M7.41,15.41L12,10.83l4.59,4.58L18,14l-6,-6 -6,6z"
        android:valueType="pathType"/>

<animated-vector xmlns:android="http://schemas.android.com/apk/res/android" 
    android:drawable="@drawable/ic_keyboard_arrow_down_black_24dp">
<target
        android:animation="@animator/anim_down_to_up"
        android:name="down"/>
</animated-vector>

<vector android:height="24dp" 
    android:tint="#05164D"
    android:viewportHeight="24.0" 
    android:viewportWidth="24.0"
    android:width="24dp" 
    xmlns:android="http://schemas.android.com/apk/res/android">
<path android:name="down" 
        android:fillColor="#FF000000" 
        android:pathData="M7.41,7.84L12,12.42l4.59,-4.58L18,9.25l-6,6 -6,-6z"/>
</vector>

<androidx.appcompat.widget.AppCompatImageButton
                        android:id="@+id/expandDepButton"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:src="@drawable/animated_vector"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:layout_constraintTop_toTopOf="parent" />

AppCompatImageButton expandDepField = view.findViewById(R.id.expandDepButton);

expandDepField.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            AppCompatImageButton btn = (AppCompatImageButton) v;
            AnimatedVectorDrawable anim = (AnimatedVectorDrawable) btn.getDrawable();

            anim.start();

        }
    });

java.lang.UnsupportedOperationException: Unsupported type: class android.util.PathParser$PathData. Only float, int or PathData value is supported for Paths.

android:propertyName="pathData"