Incrementally roll out Mobile-Content-Service and other RESTBase endpoint usage by the Android Production app. (See T118965 for beta app roll-out.)
This will be done via the MobileApp extension which provides a remote config mechanism.
We are going to add a new key `restbaseProdPercent` and increment the percentage of production app installations eligible for using the new endpoints. The config file is located at https://meta.wikimedia.org/static/current/extensions/MobileApp/config/android.json.
* [x] Stage 1: 3/24/2016: 2%
* [x] Stage 2: 3/28/2016: 25%
* [x] Stage 3: 4/4/2016: 50%
* [] Stage 4: 4/11: 100%
After deployment check https://meta.wikimedia.org/static/current/extensions/MobileApp/config/android.json
Will need a cache purge on https://en.wikipedia.org/static/current/extensions/MobileApp/config/android.json. (note the `en` instead of `meta`)
```
echo "https://en.wikipedia.org/static/current/extensions/MobileApp/config/android.json" | mwscript purgeList.php
```