packages/SystemUI/res/drawable/fingerprint_bg.xml

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     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
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     distributed under the License is distributed on an "AS IS" BASIS,
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<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
    android:shape="oval">

    <solid
      android:color="?androidprv:attr/colorSurface"/>

    <size
        android:width="64dp"
        android:height="64dp"/>
</shape>