res/drawable/widget_internal_focus_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
/*
**
** Copyright 2015, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->

<!-- Used as the widget host view background when giving focus to a child via keyboard. -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <shape android:shape="rectangle">
            <stroke android:color="#fff" android:width="2dp" />
        </shape>
    </item>
</selector>