Fix unexpected ScrollView fling behavior due to Android P bug workaround

[dhleong]

Summary

Some custom logic is applied to workaround a platform bug where velocity may be incorrect on Android P. The bug in question appears to have been fixed before Android Q was released, so we shouldn't need to apply the workaround on other versions.

As described in #34226 the workaround can adversely affect certain scroll behaviors, which can easily be reproduced when you briefly scroll one direction then quickly fling the opposite direction (see the video in the linked ticket).

This PR changes the workaround to only be applied on Android P, in order to avoid causing weird scroll behavior on versions that are not actually affected by the bug the workaround is working around.

Changelog

[Android] [Fixed] - Fix occasionally incorrect ScrollView fling behavior

Test Plan

• Repro the strange fling behavior in the current version (See video attached in Certain scroll patterns result in incorrect fling direction after Android P #34226)
• Verify that the string fling behavior is fixed with this patch
• Verify that fling behavior still works as expected on Android versions affected by the original bug, and those immediately following it (to verify that the bug being worked around was, in fact, fixed as expected).

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[cortinico]

In order to merge any pull request (code, docs, etc.), we require contributors to sign our Contributor License Agreement, and we don't seem to have one on file for you.

Hey @dhleong Can I ask you to sign the CLA so we can move this forward?

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[thomasgrivet]

Hello @dhleong I have this issue on my OnePlus 5T running Android 10, shouldn't this fix already be running on my device? Do you think I'm missing something?

[dhleong]

@thomasgrivet Sorry, I'm not sure I understand your question. This is a proposed change to fix the issue; unless you have merged it into your own fork and are running a custom build of react-native containing this fix, it's unlikely that it would be running on your device.

[facebook-github-bot]

@ryancat has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[ryancat]

From the linked issue tracker (https://issuetracker.google.com/issues/112385925?pli=1), this issue seems fixed already. We should verify that and drop the workaround all together.

Meanwhile, I think the change here makes sense. Will import and ship.

[react-native-bot]

This pull request was successfully merged by @dhleong in c7c263d.

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