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

   1 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
   2     xmlns:tools="http://schemas.android.com/tools"
   3     android:id="@+id/container"
   4     android:layout_width="match_parent"
   5     android:layout_height="match_parent"
   6     tools:context=".MainActivity"
   7     tools:ignore="MergeRootFrame" />