French Voice Selector
Selects the best available offline French voice from the device's TTS engine.
The selection algorithm:
Filters voices to keep only offline French voices (fr-FR, fr-CA, fr-BE, fr-CH).
Sorts by Voice.getQuality descending, then favours installed voices.
Among the highest-quality voices, picks the first match from preferredVoiceNames.
Falls back to the first available voice if no preferred name matches.