WordPress/src/main/res/menu/notifications_settings.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/menu_notifications_settings_search"
        app:actionViewClass="android.support.v7.widget.SearchView"
        android:icon="@drawable/ic_search_white_24dp"
        app:showAsAction="collapseActionView|ifRoom"
        android:title="@string/search_sites"
        android:visible="false"/>
</menu>