fix: slow back transitions on Android < 11 in KeyboardAwareScrollView

[kirillzyusko]

📜 Description

Improved FPS for KeyboardAwareScrollView when keyboard gets closed (and scroll position is the end of the scroll view).

💡 Motivation and Context

The fix consist of several stages. Below they are:

1️⃣ Incorrect persistentHeight update

When we reset persistentHeight in onEnd we:

• produce potential race condition (persistentHeight can be set to 0 after timing animation completion and because of that onEnd handler may not be fired at all)
• calculate progress incorrectly (it can be Infinity or NaN in last frames of animation

2️⃣ Avoid double onMove/onEnd events

If we reset persistentHeight to 0 in useAnimatedReaction (where we dispatch onEnd) -> we run animation effect again, and it may produce additional onMove/onEnd events after onEnd event. So I added if (persistentHeight.value === 0) check.

3️⃣ Don't re-calculate layout in every animation frame

When we scroll to the end of ScrollView and change padding, it seems like we do a heavy layout re-calculation. That's why I added +1 padding.

Closes #335

📢 Changelog

JS

• fixed useSmoothKeyboardHandler for Android < 10;

🤔 How Has This Been Tested?

Tested manually on Xiaomi Redmi Note 5 Pro. Also I use 2500ms instead of 250ms timing to see more detailed difference.

📸 Screenshots (if appropriate):

Original performance	With corrected useSmoothKeyboardHandler	With +1 fix
telegram-cloud-document-2-5291837971429870538.mp4	telegram-cloud-document-2-5291837971429870537.mp4	telegram-cloud-document-2-5291837971429870536.mp4

📝 Checklist

• CI successfully passed
• I added new mocks and corresponding unit-tests if library API was changed

[github-actions]

📊 Package size report

Current size	Target Size	Difference
115228 bytes	114019 bytes	1209 bytes 📈