cd android && gradlew clean && cd ..
react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res
cd android/
gradlew assembleDebug
(or you can use for release: gradlew assembleRelease)
cd android && gradlew clean && gradlew assembleRelease