[FrameworkBundle] use the new request_stack object in the GlobalVariables object
feature #9546 [FrameworkBundle] use the new request_stack service in the GlobalVariables object (hhamon)

This PR was merged into the master branch.

Discussion
----------

[FrameworkBundle] use the new request_stack service in the GlobalVariables object

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ~
| License       | MIT
| Doc PR        | ~

Commits
-------

9c2ce49 [FrameworkBundle] use the new request_stack object in the GlobalVariables object