GPII-778:  First pass at adding "deviceReporters" property for each solution.

Focus on the solutions test data for linux (linux.json).
GPII-778:  Second pass at adding "deviceReporters" properties.

Changes:
- GNOME Interface Settings (org.gnome.desktop.interface)
-- changed to gsettings-desktop-schemas (was gnome-themes-standard).

- GNOME Assistive Technology - Screen Keyboard (org.gnome.desktop.a11y.applications.onscreen-keyboard)
-- changed to gsettings-desktop-schemas (was caribou).

- GNOME Shell Keyboard Settings (org.gnome.desktop.a11y.keyboard)
-- changed to gsettings-desktop-schemas (was control-center).
GPII-778: Adding "deviceReporters" properties.

Added "gnome-shell" as the app to look for with respect to
GNOME Shell overrides (org.gnome.shell.overrides).

Similarly, changed GNOME Assistive Technology - Screen Keyboard
(org.gnome.desktop.a11y.applications.onscreen-keyboard) to
"gnome-shell" (was "gsettings-desktop-schemas").
GPII-778: Adding "deviceReporters" properties.

Fixed typo.
Merge pull request #5 from klown/device-reporter-draft2

Including deviceReporter data into linux' solutions registry