1cd android && gradlew clean && cd ..
2react-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
3cd android/
4gradlew assembleDebug 
5(or you can use for release: gradlew assembleRelease)
6cd android && gradlew clean && gradlew assembleRelease

1react-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