Fix ClassNotFound exception in Android during Release builds

[thecodrr]

Summary

This adds the @DoNotStrip annotation to disallow Proguard/R8 from stripping the AndroidUnicodeUtils class during release build and causing a ClassNotFound crash.

Changelog

[Internal] [Fixed] - Fixed ClassNotFound exception in Android during Release builds

Test Plan

[pull-bot]

	Warnings
⚠️	❔ Base Branch - The base branch for this PR is something other than master. Are you sure you want to merge these changes into a stable release? If you are interested in backporting updates to an older release, the suggested approach is to land those changes on master first and then cherry-pick the commits into the branch for that release. The Releases Guide has more information.

Generated by 🚫 dangerJS against 39ffc20

[janicduplessis]

You should also add @DoNotStrip on all the methods, I still had a crash before doing so when testing in my app.

[thecodrr]

@janicduplessis done

[mdvacca]

It looks good to me, I'm importing it!
Thanks for working on this.

[janicduplessis]

@mdvacca This actually needs to go in the 0.60 branch, I think we can just merge it directly on github. This is because we landed 2 different versions of the hermes commit in 0.60 and master.

[mdvacca]

Thanks @janicduplessis, that's why I was having problems in the import.