Android: Init Activity: Center the buttons correctly

Author: Ghabry

builds/android/app/src/main/res/layout/activity_init.xml

@@ -8,11 +8,12 @@
     android:padding="10dp"
     tools:context=".InitActivity"
     android:orientation="vertical"
-    android:gravity="center">
+    android:fillViewport="true">
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:orientation="vertical">
+        android:orientation="vertical"
+        android:gravity="center">
         <Button
             android:id="@+id/set_games_folder"
             android:layout_width="wrap_content"