Fix spec context prefix

What does this MR do and why?

Fix Rubocop error for the following files.

• jh/spec/controllers/projects/commit_controller_spec.rb
• jh/spec/controllers/projects/wikis_controller_spec.rb
• jh/spec/lib/gitlab/analytics/performance_analytics/group_report_spec.rb
• jh/spec/lib/gitlab/analytics/performance_analytics/project/report/commits_pushed_spec.rb
• jh/spec/models/content_validation/content_blocked_state_spec.rb
• jh/spec/models/jh/project_spec.rb
• jh/spec/models/jh/snippet_spec.rb
• jh/spec/presenters/snippet_blob_presenter_spec.rb
• jh/spec/requests/api/repositories_spec.rb
• jh/spec/requests/groups/analytics/performance_analytics_controller_spec.rb
• jh/spec/requests/projects/analytics/performance_analytics_controller_spec.rb
• jh/spec/serializers/diff_file_entity_spec.rb
• jh/spec/services/content_validation/commit_service_spec.rb
• jh/spec/services/content_validation/process_changes_service_spec.rb
• jh/spec/services/projects/update_service_spec.rb
• jh/spec/services/snippets/update_service_spec.rb
• jh/spec/controllers/jh/projects/notes_controller_spec.rb
• jh/spec/services/content_validation/project_visibility_changed_service_spec.rb
• jh/spec/support/shared_examples/models/content_validation_shared_examples.rb
• jh/spec/workers/content_validation/commit_service_worker_spec.rb