app/src/main/res/drawable/notification.xml
<vector android:autoMirrored="true" android:height="24dp"
android:tint="#000000" android:viewportHeight="24"
android:viewportWidth="24" android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
<path android:fillColor="@android:color/white" android:pathData="M20,2L4,2c-1.1,0 -1.99,0.9 -1.99,2L2,22l4,-4h14c1.1,0 2,-0.9 2,-2L22,4c0,-1.1 -0.9,-2 -2,-2zM18,14L6,14v-2h12v2zM18,11L6,11L6,9h12v2zM18,8L6,8L6,6h12v2z"/>
</vector>