The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/menu_settings"
android:icon="@drawable/ic_menu_preferences"
android:showAsAction="ifRoom"
android:title="@string/menu_settings" />
</menu>