[React-Native] Unable to load script from assets 'index.android.bundle'.

react native for android 抛出下面异常，解决方法：

java.lang.RuntimeException: Unable to load script from assets 'index.android.bundle'.

https://stackoverflow.com/questions/44446523/unable-to-load-script-from-assets-index-android-bundle-on-windows

1. (in project directory) mkdir android/app/src/main/assets
2. 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
3. react-native run-android