Single-variant project sync: Syncing your project with your build configuration is an important step in letting Android Studio understand how your project is structured. However, this process can be time-consuming for large projects. If your project uses multiple build variants, you can now optimize project syncs by limiting them to only the variant you have currently selected.
When syncing your project using Android Studio 3.3 Canary 6 or higher, the IDE prompts you to enable this optimization.
To enable this optimization manually, click File > Settings > Experimental > Gradle (Android Studio > Preferences > Experimental > Gradle on a Mac) and check Only resolve selected variants.
Note: This optimization currently supports projects that include only the Java programming language. If, for example, the IDE detects Kotlin or C++ code in your project, it does not automatically enable this optimization, and you should not enable it manually.