Update fragment_room_main.xml

app/src/main/res/layout/fragment_room_main.xml

@@ -2,7 +2,8 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/messageListRelativeLayout"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:background="@android:color/white">
 
     <android.support.v7.widget.RecyclerView
       android:id="@+id/messageRecyclerView"