Don't set defaultProps for default view manager values

Summary:
The Android ViewManager already has disabled set to false by default. When setting it in defaultProps we send it over for every text view, which is unnecessary.

On platforms that don't support disabled this may also cause unnecessary log noise.
Closes https://github.com/facebook/react-native/pull/16139

Differential Revision: D5944334

Pulled By: javache

fbshipit-source-id: 54c4b65f345cd284759d01d075522f5aa2f74298

Libraries/Text/Text.js

@@ -408,7 +408,6 @@ const Text = createReactClass({
       accessible: true,
       allowFontScaling: true,
       ellipsizeMode: 'tail',
-      disabled: false,
     };
   },
   getInitialState: function(): Object {