Solution

mkdir android/app/src/main/assets
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

Run

react-native run-android
Total time: 23.641 secs
'adb' is not recognized as an internal or external command,
operable program or batch file.
Starting the app (C:\Users\lenger\AppData\Local\Android\Sdk/platform-tools/adb shell am start -n com.webrowser/com.webrowser.MainActivity...
Starting: Intent { cmp=com.webrowser/.MainActivity }