Add missing countdown in RCT_ENUM_CONVERTE

[Nasseratic]

Summary

After upgrading react native to 0.72.3 the countdown mode stopped working and was fallback to time mode. My guess is that react native changed how RCT_ENUM_CONVERTER works.
Adding countdown to the enum fixed the issue.

Test Plan

Try passing countdown to mode prop

Before	After the fix

What's required for testing (prerequisites)?

What are the steps to reproduce (after prerequisites)?

Compatibility

OS	Implemented
iOS	✅
Android	❌

Checklist

• I have tested this on a device and a simulator
• I added the documentation in README.md
• I updated the typed files (TS and Flow)
• I added a sample use of the API in the example project (example/App.js)
• I have added automated tests, either in JS or e2e tests, as applicable

[vonovak]

thank you! 🙂

[vonovak]

🎉 This issue has been resolved in version 7.4.2 🎉

If this package helps you, consider sponsoring us! 🚀

[vonovak]

@Nasseratic I see you've been responding to some issues here, appreciate it! Are you on discord? If you're interested, perhaps we could chat about if / how you can / want to help out with maintaining the library, ask questions and etc? 🙂

[Nasseratic]

@vonovak Yes I am on Discord my username is nasseratic. Yes would love to chat and help with maintaining as much as I can :)

[vonovak]

@Nasseratic can you please check your discord? I sent you a friend request a week ago or so :)
my handle there is also vonovak

thank you!