google-material-design-icons/android/navigation/fullscreen/materialicons/black/res/drawable/baseline_fullscreen_18.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="18dp"
    android:height="18dp"
    android:viewportWidth="18"
    android:viewportHeight="18"
    android:tint="?attr/colorControlNormal">
  <path
      android:fillColor="@android:color/white"
      android:pathData="M4.5,11L3,11v4h4v-1.5L4.5,13.5L4.5,11zM3,7h1.5L4.5,4.5L7,4.5L7,3L3,3v4zM13.5,13.5L11,13.5L11,15h4v-4h-1.5v2.5zM11,3v1.5h2.5L13.5,7L15,7L15,3h-4z"/>
</vector>