Use Yarn for Install/Uninstall CLI if available
Summary:
Make `react-native install` and `uninstall` cli to use yarn if available (fixes #11122)
**Test plan Yarn**
1. Publish to Sinopia: https://github.com/facebook/react-native/tree/master/react-native-cli
2. react-native init AwesomeApp
3. react-native install react-native-fit-image
4. react-native uninstall react-native-fit-image
**Test plan NPM**
1. Publish to Sinopia: https://github.com/facebook/react-native/tree/master/react-native-cli
2. react-native init AwesomeAppNPM --npm
3. react-native install react-native-fit-image
4. react-native uninstall react-native-fit-image
**output (yarn.lock)**
```
> react-native install react-native-fit-image
yarn add v0.16.1
[1/4] 🔍 Resolving packages...
[2/4] 🚚 Fetching packages...
[3/4] 🔗 Linking dependencies...
[4/4] 📃 Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency
└─ react-native-fit-image@1.4.6
✨ Done in 4.11s.
rnpm-install info Module react-native-fit-image has been successfully
Closes https://github.com/facebook/react-native/pull/11174
Differential Revision: D4441872
fbshipit-source-id: 05bd30e1ad14bdbe861259c88e1f18df77cfa54f
1c249e4804