Enable locking latest artifact by default

lib/gitlab/ci/features.rb

@@ -41,11 +41,11 @@ module Gitlab
       end
 
       def self.keep_latest_artifacts_for_ref_enabled?(project)
-        ::Feature.enabled?(:keep_latest_artifacts_for_ref, project, default_enabled: false)
+        ::Feature.enabled?(:keep_latest_artifacts_for_ref, project, default_enabled: true)
       end
 
       def self.destroy_only_unlocked_expired_artifacts_enabled?
-        ::Feature.enabled?(:destroy_only_unlocked_expired_artifacts, default_enabled: false)
+        ::Feature.enabled?(:destroy_only_unlocked_expired_artifacts, default_enabled: true)
       end
 
       def self.bulk_insert_on_create?(project)