[iOS][Fix] Do not override ActivityIndicator color when setting its size

[cabelitos]

Summary

The activityIndicatorViewStyle property overrides the previous set color
if it's changed. Depending on the property set order you may end in a state
that the color property will never be respected since it first sets
the color and then the activityIndicatorViewStyle property (which overrides
the color property). In order to prevent this problem
before setting the new activityIndicatorViewStyle save the old
color and override it after activityIndicatorViewStyle is set. Thus
always respecting the user's color.

Changelog

[iOS] [Fixed] - Do not override ActivityIndicator color when setting its size

Test Plan

Using the code below on iOS notice that the last ActivityIndicator will always have its color set to white while te testID is provided

Without the patch

Notice the white -> blue transition when disabling the testID

With the patch

Color remains unchanged

import React from "react";
import { View, StyleSheet, ActivityIndicator, Button } from "react-native";

const App = () => {
  const [enableTestID, onSetEnableTestID] = React.useState(true);
  const onPress = React.useCallback(() => {
    onSetEnableTestID(!enableTestID);
  }, [enableTestID]);
  return (
    <View style={styles.container}>
      <ActivityIndicator size="large" color="red" />
      <ActivityIndicator size="small" color="red" />
      <ActivityIndicator size="small" />
      <ActivityIndicator color="green" />
      <ActivityIndicator
        key={enableTestID.toString()}
        size="large"
        color="blue"
        testID={enableTestID ? 'please work' : undefined}
      />
      <Button
        title={enableTestID ? 'Disable testID' : 'enable testID'}
        onPress={onPress}
      />
    </View>
  );
};

export default App;

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: "center",
    justifyContent: "center",
    backgroundColor: "black"
  },
});

Closes #25319

[facebook-github-bot]

@sammy-SC has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[sammy-SC]

@cabelitos thank you for fixing this!

[react-native-bot]

This pull request was successfully merged by @cabelitos in 14b0ed4.

^{When will my fix make it into a release? | Upcoming Releases}

[cabelitos]

@sammy-SC thank you very much for your approval! glad to help;