There’s just one additional step, which you’ll have to do before every release build. You need to execute the following to create a React Native bundle, which’ll be included with your native Android app:
$ react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/com/your-company-name/app-package-name/src/main/assets/index.android.bundle --assets-dest android/com/your-company-name/app-package-name/src/main/res/
Don’t forget to replace the paths with correct ones and create the assets folder if it doesn’t exist!
Now just create a release build of your native app from within Android Studio as usual and you should be good to go!