Enable MergeRequests::PipelineEntity usage

app/serializers/merge_request_poll_widget_entity.rb

@@ -20,7 +20,7 @@ class MergeRequestPollWidgetEntity < Grape::Entity
   expose :merge_user, using: UserEntity
 
   expose :actual_head_pipeline, as: :pipeline, if: -> (mr, _) { presenter(mr).can_read_pipeline? } do |merge_request, options|
-    if Feature.enabled?(:merge_request_short_pipeline_serializer, merge_request.project)
+    if Feature.enabled?(:merge_request_short_pipeline_serializer, merge_request.project, default_enabled: true)
       MergeRequests::PipelineEntity.represent(merge_request.actual_head_pipeline, options)
     else
       PipelineDetailsEntity.represent(merge_request.actual_head_pipeline, options)
@@ -28,7 +28,7 @@ class MergeRequestPollWidgetEntity < Grape::Entity
   end
 
   expose :merge_pipeline, if: ->(mr, _) { mr.merged? && can?(request.current_user, :read_pipeline, mr.target_project)} do |merge_request, options|
-    if Feature.enabled?(:merge_request_short_pipeline_serializer, merge_request.project)
+    if Feature.enabled?(:merge_request_short_pipeline_serializer, merge_request.project, default_enabled: true)
       MergeRequests::PipelineEntity.represent(merge_request.merge_pipeline, options)
     else
       PipelineDetailsEntity.represent(merge_request.merge_pipeline, options)

changelogs/unreleased/id-enable-pipelines-serializer-ff.yml

+---
+title: Serialize fewer pipeline fields for MR widget
+merge_request: 38215
+author:
+type: performance