Fix VSA error with scoped labels

This change fixes the value_streams endpoint error when one of the
stages is a label based stage where the label is a scoped label.

Changelog: fixed
EE: true

app/serializers/analytics/cycle_analytics/stage_entity.rb

@@ -57,7 +57,7 @@ module Analytics
       def html_description(event)
         options = {}
         if event.label_based?
-          label = event.label.present
+          label = event.label.present(issuable_subject: event.label.subject)
           options[:label_html] = render_label(label, link: '', small: true, tooltip: true)
         end
 

ee/spec/serializers/analytics/cycle_analytics/stage_entity_spec.rb

@@ -6,11 +6,12 @@ RSpec.describe Analytics::CycleAnalytics::StageEntity do
   subject(:entity_json) { described_class.new(Analytics::CycleAnalytics::StagePresenter.new(stage)).as_json }
 
   context 'when label based event is given' do
-    let(:label) { create(:group_label, title: 'test label') }
+    let(:label) { create(:group_label, title: 'test::label') }
     let(:stage) { build(:cycle_analytics_group_stage, group: label.group, start_event_label: label, start_event_identifier: :merge_request_label_added, end_event_identifier: :merge_request_merged) }
 
     it 'includes the label reference in the description' do
-      expect(entity_json[:start_event_html_description]).to include(label.title)
+      expect(entity_json[:start_event_html_description]).to include('test')
+      expect(entity_json[:start_event_html_description]).to include('label')
     end
   end
 end