Summary:
The reason for this change is to implement `allowFontScaling` on the Android's React Native Text component. Prior to this PR `allowFontScaling` only works for iOS.
The following link contains images of `allowFontScaling` working in Android on small, normal, large, and huge system fonts (from native Android display settings)
http://imgur.com/a/94bF1
The following link is a video of the same thing working on an Android emulator
https://youtu.be/1jTlZhPdj9Y
Here is the sample code snippet driving the video/images
```
render() {
const size = [12, 14, 16, 18];
return (
<View style={{backgroundColor: 'white', flex: 1}}>
<Text>
Default size no allowFontScaling prop (default true)
</Text>
<Text allowFontScaling={true}>
Default size allowFontScaling: true
</Text>
<Text style={{ marginBottom: 10, }} allowFontScaling={false}>
Default size allowFontScaling: false
</Text>
{ size.map(
Closes https://github.com/facebook/react-native/pull/10898
Differential Revision: D4335190
Pulled By: lacker
fbshipit-source-id: 0480809c44983644ff2abfcaf4887569b2bfede5