Inconsistent separator lines

Description

The thickness of the separator lines in FlatList is inconsistent on android. Here's another issue related to the separator: GitHub Issue.

Steps to reproduce

Add a separator to a FlatList with hairlineWidth or 1.

React Native Version

0.73.6

Affected Platforms

Runtime - Android

Output of npx react-native info

Expo 51 from snack.

Stacktrace or Logs

import React from 'react';
import {
  SafeAreaView,
  View,
  FlatList,
  StyleSheet,
  Text,
  StatusBar,
} from 'react-native';

const DATA = [...Array(100).keys()]

const Separator = () => <View style={{ height: StyleSheet.hairlineWidth, backgroundColor: '#000' }} />

const Item = ({title}) => (
  <View style={styles.item}>
    <Text style={styles.title}>{title}</Text>
  </View>
);

const App = () => {
  return (
    <SafeAreaView style={styles.container}>
      <FlatList
        data={DATA}
        renderItem={({item}) => <Item title={item} />}
        ItemSeparatorComponent={Separator}
      />
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    marginTop: StatusBar.currentHeight || 0,
  },
  item: {
    backgroundColor: 'white',
    padding: 12,
  },
  title: {
    fontSize: 20,
  },
});

export default App;

Reproducer

https://snack.expo.dev/@diegolmello/f6c27a

Screenshots and Videos

Start with the FlatList ItemSeparatorComponent behavior on Android, using the provided Expo Snack reproducer with StyleSheet.hairlineWidth and a 1-pixel separator. Compare the rendered separator thickness across the list and determine what consistent output should look like; the issue does not name implementation files or tests.