introspect: Add AnimationsEnabled property

While the gsetting is available for all who needs it, the Shell might
override it given various hueristics. Expose the decision made by the
Shell via a new property.

Intended to be used by gsd-xsettings as well as xdg-desktop-portal-gtk.

GNOME/gnome-shell!757
Status Job ID Name Coverage
  Review
passed #461256
check_commit_log

00:00:31

failed #461258
eslint

00:01:10

passed #461257
js_check

00:00:47

 
  Build
skipped #461259
build
 
  Test
skipped #461260
test
skipped #461261
test-pot
 
Name Stage Failure
failed
eslint Review
$ ./.gitlab-ci/run-eslint.sh
Generating lint report using regular configuration
Generating lint report using legacy configuration
Done.
/builds/jadahl/gnome-shell/js/ui/main.js:90:5: 'animationsSettings' is assigned a value but never used. Allowed unused vars must match /_$/u. [Error/no-unused-vars]
Uploading artifacts...
reports: found 4 matching files
Uploading artifacts to coordinator... ok
id=461258 responseStatus=201 Created token=Ydrznzzd
ERROR: Job failed: exit code 1