Android 4.3. SearchView: How remove shadow/elevation?

In my fragment I has searchView component:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.SearchView
        android:id="@+id/searchView"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginEnd="20dp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginStart="20dp"
        android:background="@drawable/settings"
        app:defaultQueryHint="@string/search_by"
        app:searchHintIcon="@null" />

</LinearLayout>

Here result:

SearchView_shadow

OK. It's work fine. But I need some tuning, remove shadow/elevation in Android 4.3. How I can do this?