Android_Drawable_Shadow.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item >
        <shape
            android:shape="rectangle">
            <solid android:color="@color/color_name" />
            <corners android:radius="7dp"/>
        </shape>
    </item>
    <item android:right="1dp" android:left="1dp" android:bottom="1dp" android:top="1dp">
        <shape
            android:shape="rectangle">
            <solid android:color="@android:color/color_name"/>
            <corners android:radius="7dp"/>
        </shape>
    </item>
</layer-list>

<!-- color_name -->

your_activity_xml.xml

<!-- add bellow two attributes into view for shadow -->
android:background="@drawable/Android_Drawable_Shadow"
android:elevation="10dp"