Once upon a time, when we didn't have all those Kotlins yet, and we wrote for Android in Java, there were talks that you can't use enums, even though they exist. They said it's too expensive in terms of memory.
And instead, it was suggested to use... just int or String constants with special @IntDef and @StringDef annotations to check at compile time that you didn't shove anything illegal in there. At runtime, shove whatever you want, that's the price for free bytes in memory.
Now this, of course, sounds like a joke. And even then it sounded like a joke, despite the fact that there was some basis for all this. Supposedly phones back then weren't cool enough to hold enums in memory. But actually, they are not even deprecated yet, take and use them.
This always seemed like penny-pinching to me, so I just calmly survived all this time using enums. Seemed to live normally, people gave me good ratings in the store. Well, now there's also several times more memory on any device than on the Mars rover, so this seems to not bother anyone anymore.