Bitmap gravity set to center not filling the screen even though the image is big enough

You can use android:gravity="fill" to cover vertical & horizontal direction

For splash image try gravity="center|fill"

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@android:color/black" />

    <item>
        <bitmap
            android:gravity="center|fill"
            android:src="@drawable/fondo" />
    </item>
</layer-list>

Try adding this to the bitmap:

android:gravity="fill_vertical"

This should fix it.

P.S. Sorry for the first answer, I edited it now.