button_stroke_appearance.xml

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

    <alpha android:fromAlpha="1.0" android:toAlpha="0.5" android:duration="20" />
    <alpha android:fromAlpha="0.5" android:toAlpha="0.04" android:duration="20" />
    <alpha android:fromAlpha="0.04" android:toAlpha="0.8" android:duration="20" />
    <alpha android:fromAlpha="0.8" android:toAlpha="0.0" android:duration="20" />
    <alpha android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="20" />

    <alpha android:fromAlpha="1.0" android:toAlpha="0.01" android:duration="40" />
    <alpha android:fromAlpha="0.01" android:toAlpha="1.0" android:duration="20" />


</set>