add window_overlay drawable

<?xml version="1.0" encoding="utf-8"?>

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item android:bottom="-1px">

        <shape android:shape="rectangle" >

            <gradient

                android:angle="270"

                android:centerColor="#10000000"

                android:endColor="#00000000"

                android:startColor="#22000000" />

        </shape>

    </item>

    <item

        android:bottom="-1dp"

        android:left="-1px"

        android:right="-1px"

        android:top="0px">

        <shape android:shape="rectangle" >

            <solid android:color="#00000000" />

            <stroke

                android:width="1px"

                android:color="#10000000" />

        </shape>

    </item>

</layer-list>

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