Random onPress handle in FlatList items while swiping pages

## Environment

expo v42.0.0

"react-native-pager-view": "5.4.0"

## Description

Random onPress handle in FlatList items while swiping pages
Especially noticeable on low-end android devices and in apps with many heavy components

## Reproducible Demo

There is a function in demo that imitate CPU intensive operation
in order for the issue to be stably reproduced in simple demo on high-end devices

https://snack.expo.dev/@sane.ecg/pager-onpress-issue

https://user-images.githubusercontent.com/764967/128613740-e384306f-a100-4b7c-9ade-7db12683d6e5.mp4

Start with the reproducible Snack demo linked in the issue and reproduce the incorrect onPress behavior while swiping pages, especially on Android with the simulated CPU-intensive operation. Compare the pressed item with the visible page and verify that swiping no longer triggers an unintended FlatList item handler under the demonstrated conditions.

Written by the indexing model from the issue text.