[FR] Reduce 158 MB FirebaseCppApp .bundle on macOS closer to its 12 MB .dll counterpart on Windows

### Feature proposal

* Firebase Component: Core / Unity

The `FirebaseCppApp-11_0_0.bundle` file located at `AppName.app/Contents/PlugIns/FirebaseCppApp-11_0_0.bundle` is a whopping **159,5 MB**, massively bloating the binary. Compared to the `FirebaseCppApp-11_0_0.dll` file located at `AppName_Data/Plugins/x86_64/FirebaseCppApp-11_0_0.dll` of **11,5 MB**, the Firebase team seems to be a little more Windows-centric internally. Please give the macOS bundle the optimizing love it deserves!

As Firebase on Windows / Mac / Linux will soon (?) allow developers like myself to release our games with Firebase on macOS, it would be great if we can save our users the download time and storage space.