Complete elasticsearch tracking refactor

In https://gitlab.com/gitlab-org/gitlab/-/merge_requests/24895 we
simplified the maintenance story for Elasticsearch record hooks.
However, we missed two places where `ElasticIndexWorker` was enqueued
directly instead of going through the new hooks.

When https://gitlab.com/gitlab-org/gitlab/-/merge_requests/24298 is
merged, it will introduce significantly more conditionality into these
hooks, so it's important that every part of GitLab uses them.

ee/app/models/ee/project_feature.rb

@@ -5,10 +5,9 @@ module EE
     extend ActiveSupport::Concern
 
     prepended do
+      # Ensure changes to project visibility settings go to elasticsearch
       after_commit on: :update do
-        if project.use_elasticsearch?
-          ElasticIndexerWorker.perform_async(:update, 'Project', project_id, project.es_id)
-        end
+        project.maintain_elasticsearch_update if project.maintaining_elasticsearch?
       end
     end
   end

ee/app/services/ee/groups/transfer_service.rb

@@ -23,21 +23,11 @@ module EE
       end
 
       override :post_update_hooks
-      # rubocop: disable CodeReuse/ActiveRecord
       def post_update_hooks(updated_project_ids)
-        ::Project.where(id: updated_project_ids).find_each do |project|
-          # TODO: Refactor out this duplication per https://gitlab.com/gitlab-org/gitlab/issues/38232
-          if ::Gitlab::CurrentSettings.elasticsearch_indexing? && project.searchable?
-            ElasticIndexerWorker.perform_async(
-              :update,
-              project.class.to_s,
-              project.id,
-              project.es_id
-            )
-          end
+        ::Project.id_in(updated_project_ids).find_each do |project|
+          project.maintain_elasticsearch_update if project.maintaining_elasticsearch?
         end
       end
-      # rubocop: enable CodeReuse/ActiveRecord
 
       def raise_ee_transfer_error(message)
         raise ::Groups::TransferService::TransferError, EE_ERROR_MESSAGES[message]

ee/spec/services/groups/transfer_service_spec.rb

@@ -79,7 +79,7 @@ describe Groups::TransferService, '#execute' do
       stub_ee_application_setting(elasticsearch_indexing: true)
     end
 
-    it 'reindexes projects' do
+    it 'reindexes projects', :elastic do
       project1 = create(:project, :repository, :public, namespace: group)
       project2 = create(:project, :repository, :public, namespace: group)
       project3 = create(:project, :repository, :private, namespace: group)