Summary:
Stateless functional components don't support refs and we need that for the component to work, it used to crash with this error message: `undefined is not an object (evaluating 'this._component.getScrollableNode')`. This makes it clear what the issue is.
Fixes some of the errors in #10635, not sure if it fixes all the cases described in the issue though.
**Test plan**
Tested that passing a component with createClass or extends Component works but passing a function causes an error.
[GENERAL] [ENHANCEMENT] [Animated] - Verify that the component passed to createAnimatedComponent is not functional
Closes https://github.com/facebook/react-native/pull/15019
Differential Revision: D6988096
Pulled By: sahrens
fbshipit-source-id: ec0ffa763245e786f44b4a1d56c0738876c25782
10b642a7af