Enable gradual diffs load by default

Enabled the graudal loading of diffs by default

app/controllers/projects/merge_requests_controller.rb

@@ -43,7 +43,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     push_frontend_feature_flag(:core_security_mr_widget_downloads, @project, default_enabled: true)
     push_frontend_feature_flag(:remove_resolve_note, @project, default_enabled: true)
     push_frontend_feature_flag(:test_failure_history, @project)
-    push_frontend_feature_flag(:diffs_gradual_load, @project)
+    push_frontend_feature_flag(:diffs_gradual_load, @project, default_enabled: true)
 
     record_experiment_user(:invite_members_version_a)
     record_experiment_user(:invite_members_version_b)

changelogs/unreleased/ph-diffsGradualLoadDefaultEnabled.yml

+---
+title: Gradually load more diffs async
+merge_request: 49476
+author:
+type: changed

config/feature_flags/development/diffs_gradual_load.yml

@@ -5,4 +5,4 @@ rollout_issue_url:
 milestone: '13.7'
 type: development
 group: group::code review
-default_enabled: false
+default_enabled: true

lib/gitlab/diff/file_collection/merge_request_diff_batch.rb

@@ -82,7 +82,7 @@ module Gitlab
         # rubocop: enable CodeReuse/ActiveRecord
 
         def batch_gradual_load?
-          Feature.enabled?(:diffs_gradual_load, @merge_request_diff.project)
+          Feature.enabled?(:diffs_gradual_load, @merge_request_diff.project, default_enabled: true)
         end
       end
     end