splash_screen fill horizontal and vertical

background_splash.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" android:layout_height="match_parent" android:layout_width="match_parent">

	<item android:drawable="@color/splashscreen_bg" />

	<!-- Set the Background Image-->
	<item android:gravity="fill_horizontal|fill_vertical" android:layout_width="match_parent" android:layout_height="match_parent">
		<bitmap android:gravity="fill_horizontal|fill_vertical" android:src="@drawable/splash" />
	</item>

</layer-list>

It was based on the tutorial from: Splash Tutorial

You can generate here