Set ActionController raise_on_unfiltered_parameters to true

What does this MR do?

Preparation for Rails 5.1+. raise_on_unfiltered_parameters setting is removed in rails and defaults to true.

Setting the setting in config/initializers/new_framework_defaults.rb doesn't work because the initialisers load after ActionController is loaded. Related issue: https://github.com/rails/rails/issues/33283. For now I placed it in config/application.rb, but it can be removed once on Rails 5.1+.

Added a force unlock lfs spec as the specs passed with or without force being a permitted param.

Also created an EE commit: jlemaes/gitlab-ee@c494cea9, but there are no additional failures because of this setting.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer