device/drawable-anydpi-v21/ic_brightness_low_black_24dp.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="24dp"
        android:height="24dp"
        android:viewportWidth="24.0"
        android:viewportHeight="24.0">
    <path
        android:fillColor="#FF000000"
        android:pathData="M20,15.31L23.31,12 20,8.69V4h-4.69L12,0.69 8.69,4H4v4.69L0.69,12 4,15.31V20h4.69L12,23.31 15.31,20H20v-4.69zM12,18c-3.31,0 -6,-2.69 -6,-6s2.69,-6 6,-6 6,2.69 6,6 -2.69,6 -6,6z"/>
</vector>