Summary:
> Explain the **motivation** for making this change. What existing problem does the pull request solve?
`AnimatedValueX` has `removeAllListeners()` which is a convenient way to do cleanup when components unmount, but `AnimatedValueXY` was missing a similar method which doesn't really make sense. This change makes the two classes more similar, less confusing and more convenient.
Closes https://github.com/facebook/react-native/pull/11783
Differential Revision: D4397188
fbshipit-source-id: d10a0c9c7e0a83af015ec04f6facf965d95ea984