Bug 911055 - [Dialer]DuT doesn allow to dial a <<pause>>

Not currently but very good catch ) The DTMF_SEPARATOR_PAUSE_DURATION is 3 seconds and the problem was having timeouts less than 1 seconds long since it seems the backend does not allow them when the apps are in the background. This is the reason why the real tones (not the pauses) are played by the backend ;)