add rubric range feature flag to cache key.
add rubric range feature flag to cache key.

Fixes: PFS-8712

Test Plan:
In environment with page caching -
1.  View rubric page (account or course
    shouldn't matter)
2.  Turn on "rubric criterion range" in
    account features.
3.  Wait 5 minutes and View rubric page
    - range option should be available.
4.  Turn off "rubric criterion range".
5.  Wait 5 minutes and Reload rubric page
    - range option should not be available.

To enable caching on a local dev environment:
In config/environments/development.rb:

1) config.cache_classes = true

2) config.action_controller.perform_caching = true

Change-Id: I43114086c1df903cc4ee103c0e63ce4f0018d8e5
Reviewed-on: https://gerrit.instructure.com/127456
Tested-by: Jenkins
Reviewed-by: Matt Berns <e53c8988cd428dde240324ce2797c8eb7073560f@instructure.com>
QA-Review: Aiona Hernandez <98b9aa912288cf8559d433e7314527a7eee0ac9d@instructure.com>
QA-Review: Andrew Porter <747194079243b0beca9081f8cd559c020b06a314@instructure.com>
Product-Review: Sidharth Oberoi <b9947257dd0ff1b6a5d899864f5ca846b60f0be3@instructure.com>

venturehive/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms