ringtone while starting a calling

[jakobroehrl]

On android there is a ringtone when I start a call till it is established, like on the telephone.

[maprambo]

I think such a tone would greatly improve user feedback. I created a sound for dialing and one for ending a call. After that, I realized one could just use the same sound as for Android. Nevertheless, here they are. Use them or drop them.

sounds.zip

[SystemKeeper]

Android commit for reference https://github.com/nextcloud/talk-android/commit/642146de02a01de998d5b84ce53d5597d4d17b9e