@react-native-picker/picker/android/src/main/res/drawable/ic_dropdown.xml

React Native Picker for iOS, Android, macOS, and Windows

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="48dp"
    android:height="48dp"
    android:viewportWidth="48"
    android:viewportHeight="48"
    android:tint="?attr/colorControlNormal">
  <path
      android:fillColor="@android:color/black"
      android:pathData="M19,22l5,5 5,-5z"/>
</vector>