Fix tts audition (#4656)

Co-authored-by: luowei <glpat-EjySCyNjWiLqAED-YmwM>
Co-authored-by: crazywoola <427733928@qq.com>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>

api/controllers/console/app/audio.py

             response = AudioService.transcript_tts(
                 app_model=app_model,
                 text=request.form['text'],
-                voice=request.form.get('voice'),
+                voice=request.form['voice'] if request.form.get('voice') else app_model.app_model_config.text_to_speech_dict.get('voice'),
                 streaming=False
             )
 

api/controllers/console/explore/audio.py

             response = AudioService.transcript_tts(
                 app_model=app_model,
                 text=request.form['text'],
-                voice=request.form.get('voice'),
+                voice=request.form['voice'] if request.form.get('voice') else app_model.app_model_config.text_to_speech_dict.get('voice'),
                 streaming=False
             )
             return {'data': response.data.decode('latin1')}

api/controllers/web/audio.py

                 app_model=app_model,
                 text=request.form['text'],
                 end_user=end_user.external_user_id,
-                voice=request.form.get('voice'),
+                voice=request.form['voice'] if request.form.get('voice') else app_model.app_model_config.text_to_speech_dict.get('voice'),
                 streaming=False
             )