[General] Fix relations not being applied in api V1

[j-piasecki]

Description

1. configureRelations wasn't called after creating the gesture, only after the update.
2. filterConfig isn't idempotent, and calling it a second time resulted in the relations arrays being cleared. Adds a simple selectProperties util to use instead.

Test plan

Test legacy Multitap example

[Copilot]

Pull request overview

This PR fixes legacy (API v1) gesture-handler “relations” (e.g. waitFor, simultaneousHandlers, blocksHandlers) not being applied on initial handler creation, and prevents relations from being accidentally cleared by re-filtering already-filtered config.

Changes:

• Call RNGestureHandlerModule.configureRelations immediately after createGestureHandler so relations are applied on first mount.
• Stop using filterConfig to re-filter relation props during updates; use a new selectProperties helper to pick relation fields without re-transforming them.
• Add selectProperties utility to handlers/utils.ts.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
packages/react-native-gesture-handler/src/handlers/utils.ts	Adds selectProperties helper intended to avoid non-idempotent filterConfig behavior for relations.
packages/react-native-gesture-handler/src/handlers/createHandler.tsx	Applies relations on creation and switches update-time relation extraction to selectProperties.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[m-bert]

filterConfig isn't idempotent

And I think it should be, right? Anyway, that's probably not for now. Leaving ✅ so it is not blocked before release.

Also, do you know why Android worked anyway?

[j-piasecki]

And I think it should be, right?

It wouldn't hurt, but I don't know if something relies on it at this point.

Also, do you know why Android worked anyway?

No 😞