session-android/res/anim/camera_capture_button_grow.xml

<?xml version="1.0" encoding="utf-8"?>

<set xmlns:android="http://schemas.android.com/apk/res/android">
    <scale
        android:duration="100"
        android:interpolator="@android:anim/decelerate_interpolator"
        android:fromXScale=".85"
        android:fromYScale=".85"
        android:toXScale="1.0"
        android:toYScale="1.0"
        android:pivotX="50%"
        android:pivotY="50%" />
</set>