snailmail/app/src/main/res/menu/activity_main_drawer.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:showIn="navigation_view">

    <group android:checkableBehavior="single">
        <item
            android:id="@+id/nav_home"
            android:icon="@drawable/inbox_icon"
            android:title="@string/drawer_inbox" />
        <item
            android:id="@+id/nav_gallery"
            android:icon="@drawable/sent_icon"
            android:title="@string/drawer_sent" />
        <item
            android:id="@+id/nav_slideshow"
            android:icon="@drawable/drafts_icon"
            android:title="@string/drawer_drafts" />
    </group>
</menu>