res/drawable/widget_configuration_background.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
     SPDX-FileCopyrightText: 2023 The LineageOS Project
     SPDX-License-Identifier: Apache-2.0
-->

<shape android:shape="rectangle"
  xmlns:android="http://schemas.android.com/apk/res/android">
    <stroke
        android:width="1dp"
        android:color="@color/system_neutral2_700" />
    <solid android:color="@android:color/transparent"/>
    <corners android:radius="@dimen/widget_configuration_background_corner_radius" />
</shape>