Summary:
This PR is related to the multitude of crashes (#10016, #9751, #9882).
From my understanding, we should be using a strong reference when calling `decodeImageData` or we could be calling the method on a deallocated instance.
PR #9751 have mitigated this by adding a fail-safe, but I think the culprint is the weak reference, which this PR fixes.
Tested on iOS only, since it doesn't touch Android.
Closes https://github.com/facebook/react-native/pull/10147
Differential Revision: D3938763
fbshipit-source-id: 7389d4ae7a98926014401a1fe0cbbdcdd5ee6a01