[googletts] Use returned sound to get play informations (#11877)

[googletts] Use returned sound to get play informations (#11877)

* [googletts] Use real sound returned to get play informations (#10015)

When google tts returns a wav file, it is now parsed to get correct informations about it.(mandatory for playing it with at least the System speaker audio sink)
Close #10015

* Fix a regression, as the WAV fix was incorrectly applied to the MP3 file

Signed-off-by: Gwendal Roulleau <gwendal.roulleau@gmail.com>