packages/SystemUI/res-keyguard/drawable/bubble_hour_hand.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:height="340dp"
    android:width="340dp"
    android:viewportHeight="340"
    android:viewportWidth="340">
    <path
        android:pathData="M170,40m-39,0a39,39 0,1 1,78 0a39,39 0,1 1,-78 0"
        android:strokeColor="#000000"
        android:strokeWidth="2"/>
</vector>