Flexible toolbar and SearchView

FlexibleSearchView.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="#f2f2f2">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar_main"
        android:layout_width="match_parent"
        android:layout_height="@dimen/action_bar_size_x2"
        android:background="@color/colorPrimary"
        android:minHeight="?attr/actionBarSize" />

    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="24dp"
        android:layout_marginRight="24dp"
        android:layout_marginBottom="16dp"
        android:layout_marginTop="?attr/actionBarSize"
        app:cardBackgroundColor="@android:color/white">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <SearchView
                android:id="@+id/searchview"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="@android:color/white" />

            <View
                android:layout_width="match_parent"
                android:layout_height="1dp"
                android:background="#000000"
                android:layout_marginTop="-1dp"
                android:alpha="0.12"/>

        </LinearLayout>

    </android.support.v7.widget.CardView>


</RelativeLayout>