"grave" and "Above_Tab" is not detected as conflict in Keyboard Shortcut Settings

[Joboy Jordan]

"grave" and "Above_Tab" is not detected as conflict in Keyboard Shortcut Settings causing for "<Super> + `" shortcut to trigger both "['<Super>grave']" and "['<Super>Above_Tab']" keyboard shortcuts intermittently and unpredictably

HOW TO REPLICATE:
- In Keyboard Settings UI, change the "Hide Window" action to use "<Super> + `" (key above tab)
- Doing this will result in dconf to have a value of "minimize" dconf key to:
  - [org/gnome/desktop/wm/keybindings]
  - minimize=['<Super>grave']
- At this point I'm expecting Keyboard Settings UI to detect this as conflict and remove keyboard shortcut for "switch-group"/"Switch windows of an application" which has default keyboard shortcut of:
  - ['<Super>Above_Tab','<Alt>Above_Tab']

ROOT CAUSE:
- from Keyboard Settings UI, "`" key produces "grave" in dconf settings
- while default keyboard shortcuts use "Above_Tab" or via dconf-editor

WORKAROUND:
- just remove manually the shortcut ['<Super>Above_Tab'] from switch-group via dconf-editor or disable from Keyboard Settings UI

SYSTEM DETAILS:
$> lsb_release -rd
Description: Ubuntu 18.04.1 LTS
Release: 18.04

$> apt-cache policy gnome-settings-daemon
gnome-settings-daemon:
  Installed: 3.28.1-0ubuntu1
  Candidate: 3.28.1-0ubuntu1
  Version table:
 *** 3.28.1-0ubuntu1 500
        500 http://ph.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status