Add default google engine and Android 11 intent.

[joaocps]

Some mobile phone brands, for example samsung, bring their native tts engine and not google's. Often with some flaws in terms of quantity and quality in the languages/locale.

I came across this problem when the pt-PT locale and the samsung phone had its own default engine on the device and it gave a null response. The google engine must be used to have access to all the languages ​​present in the documentation.

Also faced faced some compatibility problems related with the last android version:

Apps targeting Android 11 that use text-to-speech should declare TextToSpeech.Engine.INTENT_ACTION_TTS_SERVICE in the queries elements of their manifest.