Allow GestureHandlerRootView to be manually made active

[j-piasecki]

Description

This PR allows users to override whether a particular GestureHandlerRootView is enabled or not. By default, only the topmost root view would be active, allowing all gestures to interact with each other.

The problem with that approach is that if any of the native views underneath calledrequestDisallowInterceptTouchEvent, all gestures would be canceled. It comes from the fact that requestDisallowInterceptTouchEvent calls are propagated up the view hierarchy and we expect GestureHandlerRootView to be relatively close to the top.

The simple solution would be to add another root view underneath the view that may call requestDisallowInterceptTouchEvent to prevent gestures from being canceled, this, however, resulted in two problems:

• the inner root view would not be enabled
• after adding the option to enable it manually, both root views would start handling the event, resulting in duplicated event streams

I've fixed the second problem by adding checks at the beginning of extractGestureHandlers and traverseWithPointerEvents to ensure that we're not extracting gestures attached under another enabled root view.

This allows for solving the problem described in #2383.

Test plan

Tested on the reproduction from #2383

[m-bert]

LGTM

[lpatrun]

Can we expect this to be merged? It's approved after all
🙈

[j-piasecki]

Actually, I'm not sure if this is the best solution to this problem. I'll try to get back to it in the near future to see if I can find other approaches to this.

[lpatrun]

@j-piasecki thank you for the quick response