Fix about layout integration

vlc-android/res/layout/about_main.xml

 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
     <ScrollView
@@ -113,4 +113,4 @@
     </ScrollView>
 
     <include layout="@layout/tv_time" />
-</FrameLayout>
+</merge>