I had to make my VideoView sit in a RelativeLayout in order to make the chosen answer work.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<VideoView android:id="@+id/videoViewRelative"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
</VideoView>
</RelativeLayout>
As given here: Android – How to stretch video to fill VideoView area Toggling between screen sizes would be as simple as changing the layout parameters as given in the chosen answer.