Enable reanimated/rn feature flags to allow accurate scroll events tracking

[kmagiera]

This PR fixes an issue with the sticky day selector jumping intermittently when scrolling past the top position of the selector.

One change is to use Animated.FlatList component as opposed to creating one using Animated.createAnimatedComponent. The version that reanimated exports has the throttling defaults set properly such that it avoids event throttling.

In addition, we enable feature flags in react native and reanimated that results in the direct ui thread updates from being delayed. Read more here: https://docs.swmansion.com/react-native-reanimated/docs/guides/feature-flags/#disable_commit_pausing_mechanism

[betomoedano]

Just tested this on a physical device and the issue is fixed!

LGTM

[kmagiera]

Apparently this will require native update and also effectively turns off the iOS prebuilds for the project. I hope the flag will be enabled in the next RN release though

[sync]

Seems like just the change to this file fixes the sticky header jumping (using react-native FlatList), without having to change app.config.ts and package.json

[hirbod]

That change will definitely not fix the issue, its more like this one optimized it (but its still happening randomly): c4509a4

[kmagiera]

unfortunately both of these updates are necessary. The changes from c4509a4 while offload the JS thread communication they still don't impact the UI updates from being applied on time. I updated the PR description with some links so you can learn more why these changes are necessary

[hirbod]

@kmagiera can you elaborate on "has the throttling defaults set properly"? The only thing I see is that it sets scrollEventThrottle to 1 instead of 50 (and only if not overwritten).