[tts] ios tts and audio sources conflicts

[juaoose]

Whenever TTS plays, it will mute and pause any audio source, forcing you to refresh audio sources.

[juaoose]

Looks like opening the web preview and unmuting it also stops TTS

[juaoose]

Do you think maybe the conflict could be resolved by using these settings for TTS?

• flutterTts.setSharedInstance(true);
• _tts.setIosAudioCategory(IosTextToSpeechAudioCategory.playback, ...somethingsomething) Looks like this is why TTS might not play in the background even when the plist is configured.

See https://developer.apple.com/documentation/avfaudio/avaudiosession

[kevmo314]

I think it's worth a shot