Fix checking pointer event feature flag
Fix checking pointer event feature flag

Summary:
Changelog: [Internal]

The feature flag is a function not a boolean, flow didn't caught it..

Reviewed By: rbalicki2

Differential Revision: D41172775

fbshipit-source-id: b8a3365ab65049706b59e7e859f5f931ecab8360

facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native,facebook/react-native