Fix final few problematic `React.ElementRef` in react-native (#47473)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47473

For example,

```
declare function C<T>(ref: React.RefSetter<Set<T>>): React.Node;

type T = React.ElementRef<typeof C>
```

Previously Flow will evaluate `T` to `Set<mixed>`, by automatically replacing generic types with their upper bounds. But in the future it might be replaced with `empty`.

This diff cleans up instances like this in react-native codebase.

Changelog: [Internal]

Reviewed By: alexmckenley

Differential Revision: D65562571

fbshipit-source-id: bca2f4f022a5a23a5aa40886f5661899cb315f2e