FreeSWITCH

FS-7720 improve play_and_detect_speech to set current_application_response channel variable as follows:

    "USAGE ERROR": bad application arguments
    "GRAMMAR ERROR": speech recognizer failed to load grammar
    "ASR INIT ERROR": speech recognizer failed to allocate a session
    "ERROR": any other errors

  This is useful for determining that play_and_detect_speech failed because the recognizer is out of licenses
  giving the developer a chance to fall back to traditional DTMF menu navigation.