Fix setImmediate/clearTimeout mismatch in NativeAnimatedHelper (#46525)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46525

While debugging I noticed that my setTimout was being cleared by someone else. Upon further inspection I found NativeAnimatedHelper which was mismatching setImmediate timer handle with a clearTimeout. This isn't safe and needs to be fixed.

I used this to rename the timer to be more clear to reduce the changes of mismatches.

Changelog:
[General][Fixed] - Fix setImmediate/clearTimeout mismatch in NativeAnimatedHelper that could clear an unrelated setTimeout.

Reviewed By: javache, yungsters

Differential Revision: D62775703

fbshipit-source-id: c1669c60bd08f13a59dd6159be2f471a6c1beebd