app/src/main/res/menu/settings_menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/menu_settings"
android:title="Settings"
app:showAsAction="always"
android:windowActionBarOverlay="false"
android:icon="@drawable/ic_settings_white_24dp"/>
</menu>