Adrien Béraud authored Feb 02, 2016 and Guillaume Roguez committed Feb 02, 2016

On Android, if the device is in silent or ringtone mode,
the ringtone device should be muted, while keeping the possibility
to hear the peer during a call.

Tuleap: #262
Change-Id: Ie64da9cb3a940b4749bb163f169474ca237c4b37