Fix Style/FrozenStringLiteralComment violations in rubocop

.rubocop_manual_todo.yml

rubocop/cop/avoid_keyword_arguments_in_sidekiq_workers.rb

rubocop/cop/gitlab/finder_with_find_by.rb

rubocop/cop/gitlab/keys-first-and-values-first.rb

rubocop/cop/migration/add_concurrent_foreign_key.rb

rubocop/cop/migration/add_concurrent_index.rb

rubocop/cop/migration/add_index.rb

rubocop/cop/migration/add_timestamps.rb

rubocop/cop/migration/datetime.rb

rubocop/cop/migration/hash_index.rb

rubocop/cop/migration/remove_column.rb

rubocop/cop/migration/remove_concurrent_index.rb

rubocop/cop/migration/remove_index.rb

rubocop/cop/migration/safer_boolean_column.rb

rubocop/cop/migration/timestamps.rb

rubocop/cop/migration/update_column_in_batches.rb

rubocop/cop/project_path_helper.rb

rubocop/migration_helpers.rb

rubocop/qa_helpers.rb