Adjust Checkbox component to align with UX specs

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

<!--

    Copyright 2019 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.

-->

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

    <item

        android:width="@*android:dimen/car_primary_icon_size"

        android:height="@*android:dimen/car_primary_icon_size"

        android:drawable="@drawable/btn_check_material_anim"/>

    <item

        android:width="@*android:dimen/car_primary_icon_size"

        android:height="@*android:dimen/car_primary_icon_size"

        android:drawable="@drawable/car_checkbox_background"/>

</layer-list>

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

<!--

    Copyright 2021 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.

-->

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_focused="true" android:state_pressed="true">

        <shape android:shape="rectangle">

            <solid android:color="#8A0041BE" />

            <stroke android:width="4dp" android:color="#0041BE" />

        </shape>

    </item>

    <item android:state_focused="true">

        <shape android:shape="rectangle">

            <solid android:color="#3D0059B3" />

            <stroke android:width="8dp" android:color="#0059B3" />

        </shape>

    </item>

</selector>