Stop stubbing custom_roles feature flag

What does this MR do and why?

The custom_roles feature flag does not exist or was removed but some tests remain that continue to stub this feature flag. The change in this MR updates these specs to stub the custom_roles licensed feature instead of the feature flag that is not defined.

Fixes:

モ bundle exec rspec ee/spec/policies/group_policy_spec.rb ee/spec/policies/project_policy_spec.rb
Run options: include {:focus=>true}

All examples were filtered out; ignoring {:focus=>true}

Test environment set up in 1.008403666 seconds
...............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................**......................................................................................................................................................................................................................................................................................................................................................DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
..DEPRECATION WARNING: Invalid Feature Flag custom_roles stubbed (called from each at /home/mokhax/src/gitlab.com/gitlab-org/gitlab-development-kit/gitlab/spec/support/helpers/stub_feature_flags.rb:49)
...........................................................................................................................................................................................................................................................................

Pending: (Failures listed here are expected and do not affect your suite's status)

  1) ProjectPolicy behaves like resource with requirement permissions when requirements feature is enabled with guest with user as author/assignee
     # Only applicable for requirement object
     # ./ee/spec/support/shared_examples/policies/requirement_policy_shared_examples.rb:74

  2) ProjectPolicy behaves like resource with requirement permissions when requirements feature is enabled with guest with user as author/assignee
     # Only applicable for requirement object
     # ./ee/spec/support/shared_examples/policies/requirement_policy_shared_examples.rb:75


Finished in 4 minutes 44.7 seconds (files took 11.32 seconds to load)
1899 examples, 0 failures, 2 pending

Related:

• [Feature flag] Roll out and clean up Customizab... (#372548 - closed) • Jessie Young • 15.10 • Needs attention
• Decide when to roll out custom roles feature fl... (#383307 - closed) • Jessie Young • 15.9 • On track

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