Android: Cannot change language through the API.

## Issue: Android, Cannot change language through the API.
Expected
The language should be set to what I provide, like “es”.
Actual
Uses the default language “en”

Issue confirmed in version: MathCat v0.6.3
Working in version: MathCat v0.5.3

Target OS: Android API 21 (Fire OS & Google Android)
Build OS: Mac (Sonma) & Windows 11
Rust-C: Mac x86_64 (1.80.1) & Windows MSVC (1.80.1),
Build tools: NDK 27, Cargo-NDK, MathCat_C

### Message
Hi, I’m having trouble changing the language from the default language “en” (English) on Android trough MathCat_c with the latest MathCat v0.6.3, the default language “en” (English) works fine as it’s correctly parsing the MathML code. It worked fine with the old MathCat v0.5.3 which was before the zipped Rules items. So, I guess there have been more changes under the hood.

I can confirm that unzipping the Language works fine, as I can see the unzipped files in “es” (Spanish). So, I enabled logs on Android to see what’s happening. The summary from the logs is that it seems to be changing between “Auto” and “en” (English) for some reason in “fn find_file” inside prefs.rs, and it loads something from “Rules/prefs.yaml”.

## Files
[MathCat - logs.txt](https://github.com/user-attachments/files/16865647/MathCat.-.logs.txt)