The new app publishing format, the Android App Bundle, is a more efficient way to build and release your app. The Android App Bundle lets you more easily deliver a great experience in a smaller app size, allowing for the huge variety of Android devices available today. It's easy to switch. You don’t need to refactor your code to start benefiting from a smaller app.
Available in Android Studio 3.2 or later and the Unity 2018.3 beta release.