We can't use data class as we want multiple layers of fallbacks, e.g. zh-HK -> zh-TW -> en.

We can use data class.copy, but it seems data class hits jvm max method limit.

@FooIbar reimplemented, PTAL.

Pros: cleanest way for translators to add new strings
Cons: 1. No compiler check to avoid us mutate strings 2.No compiler check to avoid duplicate translations

dex size decrease for 100KB as well

I don't think this is the way. How do the translators check for missing translations? They could just remove theby EnStrings before.

I don't think translators will use IDE or check for compiler message.
They just compare the whole file with EN file, so the cleanest way to add is better