circle.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="20dp" />
    <solid android:color="@color/grey" />
    <size
        android:width="40dp"
        android:height="40dp" />
</shape>