Summary:
This PR addresses issue #9265.
Negated the condition that checks if `_hostViews` exists so that `_hostViews` will be allocated only if it doesn't exist
Closes https://github.com/facebook/react-native/pull/9295
Differential Revision: D3686214
fbshipit-source-id: ec0caac99d231786eefad023f3f0ed44a79f687e