The introduction of the AGP Upgrade Assistant in Android Studio 4.2 allowed users to modify their build files if necessary to account for the switch of default in AGP to use Java 8 (rather than the historic default of Java 7), as well as to recommend modifying dependency configurations from the deprecated compile to whichever of api and implementation was appropriate, and to support migration of projects from fabric to Firebase Crashlytics. Conditionally adding the Google maven repository to the Gradle repositories, if the AGP version was being upgraded from a version earlier than 3.0.0 to one later than 3.0.0.Upgrading the version of Gradle to the version associated with that version of AGP.Upgrading the version of AGP to the latest version.The AGP Upgrade Assistant was introduced in Android Studio 4.2, extending or substantially replacing existing infrastructure which special-cased three actions to take:

The AGP Upgrade Assistant is a collection of infrastructure, user interfaces and somewhat reusable components for the specific purpose of updating projects consistently in response to a user request to upgrade the version of the Android Gradle Plugin used in that project.

Gradle update android studio