Add comment for changes id in main_activity.xml.

ui/src/main/res/layout-sw600dp/main_activity.xml

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!--add master_detail_wrapper id in CoordinatorLayout and remove that id in LinearLayout-->
 <androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -6,6 +7,7 @@
     android:layout_height="match_parent"
     tools:context=".activity.MainWireGuardActivity">
 
+    <!-- android:id="@+id/master_detail_wrapper" -->
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"