No way to disable system startup sound

Package gnome-session-canberra contains /usr/share/gdm/autostart/LoginWindow/libcanberra-ready-sound.desktop file, which plays extremely annoying drum sound at every boot.

This is a problem (at least for me, but I think for many others), and there is no way to disable this without changing package-provided files. Moreover, this package (gnome-session-canberra) couldn't be removed without breaking ubuntu-desktop package (I'll file separate bugreport for this).

Propose: Create a way do disable those sounds in a user-available way. The simplest way I can propose is to mark /usr/share/gdm/autostart/LoginWindow/libcanberra-ready-sound.desktop as conffile, which will keep user changes in this file during package upgrade.

More user-friendly (visible) changes would be appreciated too, but conffile should, at least, give some way to manage loud 'blam-blam' at boot.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-session-canberra 0.30-3ubuntu1 [modified: usr/share/gdm/autostart/LoginWindow/libcanberra-ready-sound.desktop]
ProcVersionSignature: Ubuntu 4.12.0-12.13-generic 4.12.8
Uname: Linux 4.12.0-12-generic x86_64
ApportVersion: 2.20.7-0ubuntu1
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Sun Sep 3 12:55:31 2017
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
EcryptfsInUse: Yes
InstallationDate: Installed on 2017-06-22 (73 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
SourcePackage: libcanberra
UpgradeStatus: No upgrade log present (probably fresh install)