app/src/main/res/values/mainImageViewStyle.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="mainImageViewStyle">
<item name="android:layout_width">match_parent</item>
<item name="android:layout_height">0dp</item>
<item name="android:layout_weight">1</item>
<item name="android:layout_gravity">center</item>
</style>
</resources>