app/src/main/res/anim/bouncy_button.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >
<scale
android:duration="100"
android:fromXScale="1.0"
android:toXScale="0.98"
android:fromYScale="1.0"
android:toYScale="0.98"
android:pivotX="50%"
android:pivotY="50%" />
</set>