No need to do any coding for playing video to full screen mode
Apply the following layout format over the xml containing the videoview it will for sure will play the video in full screen mode. as it is running mine.
<?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/myvideoview"
android:layout_width="fill_parent"
android:layout_alignParentRight="true"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="true"
android:layout_height="fill_parent">
</VideoView>
</RelativeLayout>
Plus adding the mediacontroller will also give you the controller to use.