main_menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto" >
    
    <!-- add the following item to your menu.xml -->
    
    <item
        android:id="@+id/ic_group"
        android:icon="@drawable/actionbar_group_icon.xml"
        android:title="@string/group_title"
        app:showAsAction="always" />
</menu>