core/res/res/anim/btn_radio_to_on_mtrl_ring_outer_path_animation.xml

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <set
        android:ordering="sequentially" >
        <objectAnimator
            android:duration="166"
            android:propertyName="strokeWidth"
            android:valueFrom="2.0"
            android:valueTo="18.0"
            android:valueType="floatType"
            android:interpolator="@interpolator/btn_radio_to_on_mtrl_animation_interpolator_0" />
        <objectAnimator
            android:duration="16"
            android:propertyName="strokeWidth"
            android:valueFrom="18.0"
            android:valueTo="2.0"
            android:valueType="floatType"
            android:interpolator="@android:interpolator/fast_out_slow_in" />
        <objectAnimator
            android:duration="316"
            android:propertyName="strokeWidth"
            android:valueFrom="2.0"
            android:valueTo="2.0"
            android:valueType="floatType"
            android:interpolator="@android:interpolator/fast_out_slow_in" />
    </set>
</set>