fix: headphones carousel example

[CarlosSLoureiro]

Summary

Fix de logic of background color from circle component at the headphones carousel example.

Motivation

I've reading the code of the headphones carousel example and I understood that the color of the circle must change due to a code line will be mentioned below in this PR.

Test Plan

Just try to execute the mentioned example.

Checklist

• [X] I have tested this on a device and a simulator (yes, in Android and iOS)
• [X] I added the documentation in README.md (yes, updated the readme gif example)
• [ ] I updated the typed files (TS and Flow) (No)

[troZee]

@CarlosSLoureiro could you resolve conflicts 🙏

Moreover, the iOS pipeline failed. Could you check that?

[CarlosSLoureiro]

@troZee I think it's done.

[troZee]

LGTM. Please address those 2 comments: https://github.com/callstack/react-native-pager-view/pull/754#discussion_r1308494086 https://github.com/callstack/react-native-pager-view/pull/754#discussion_r1308493664