This will show you how to configure keyboard shortcuts in Ubuntu via the command line
List the available keys
list-recursively org.gnome.settings-daemon.plugins.media-keys
Change the multimedia keys
Previous settings
org.gnome.settings-daemon.plugins.media-keys home 'XF86Explorer'
org.gnome.settings-daemon.plugins.media-keys media 'XF86AudioMedia'
org.gnome.settings-daemon.plugins.media-keys next 'XF86AudioNext'
org.gnome.settings-daemon.plugins.media-keys pause 'XF86AudioPause'
org.gnome.settings-daemon.plugins.media-keys play 'XF86AudioPlay'
org.gnome.settings-daemon.plugins.media-keys previous 'XF86AudioPrev'
org.gnome.settings-daemon.plugins.media-keys stop 'XF86AudioStop'
org.gnome.settings-daemon.plugins.media-keys volume-down 'XF86AudioLowerVolume'
org.gnome.settings-daemon.plugins.media-keys volume-mute 'XF86AudioMute'
org.gnome.settings-daemon.plugins.media-keys volume-up 'XF86AudioRaiseVolume'
org.gnome.settings-daemon.plugins.media-keys www 'XF86WWW'
New settings
gsettings set org.gnome.settings-daemon.plugins.media-keys home ''
gsettings set org.gnome.settings-daemon.plugins.media-keys media ''
gsettings set org.gnome.settings-daemon.plugins.media-keys next ''
gsettings set org.gnome.settings-daemon.plugins.media-keys pause ''
gsettings set org.gnome.settings-daemon.plugins.media-keys play ''
gsettings set org.gnome.settings-daemon.plugins.media-keys previous ''
gsettings set org.gnome.settings-daemon.plugins.media-keys stop ''
gsettings set org.gnome.settings-daemon.plugins.media-keys www ''
and maybe these
gsettings set org.gnome.settings-daemon.plugins.media-keys volume-down ''
gsettings set org.gnome.settings-daemon.plugins.media-keys volume-mute ''
gsettings set org.gnome.settings-daemon.plugins.media-keys volume-up ''