Create system note metadata - EE specific

app/models/system_note_metadata.rb

 class SystemNoteMetadata < ActiveRecord::Base
   ICON_TYPES = %w[
     commit merge confidentiality status label assignee cross_reference
-    title time_tracking branch milestone discussion task moved
+    title time_tracking branch milestone discussion task moved approvals
   ].freeze
 
   validates :note, presence: true

app/services/system_note_service.rb

@@ -482,12 +482,13 @@ module SystemNoteService
   def approve_mr(noteable, user)
     body = "approved this merge request"
 
-    create_note(noteable: noteable, project: noteable.project, author: user, note: body)
+    create_note(NoteSummary.new(noteable, noteable.project, user, body, action: 'approvals'))
   end
 
   def unapprove_mr(noteable, user)
     body = "unapproved this merge request"
-    create_note(noteable: noteable, project: noteable.project, author: user, note: body)
+
+    create_note(NoteSummary.new(noteable, noteable.project, user, body, action: 'approvals'))
   end
 
   private

spec/services/system_note_service_spec.rb

@@ -794,7 +794,9 @@ describe SystemNoteService, services: true do
     let(:noteable)    { create(:merge_request, source_project: project) }
     subject { described_class.approve_mr(noteable, author) }
 
-    it_behaves_like 'a system note'
+    it_behaves_like 'a system note' do
+      let(:action) { 'approvals' }
+    end
 
     context 'when merge request approved' do
       it 'sets the note text' do
@@ -806,7 +808,9 @@ describe SystemNoteService, services: true do
   describe '.change_time_estimate' do
     subject { described_class.change_time_estimate(noteable, project, author) }
 
-    it_behaves_like 'a system note'
+    it_behaves_like 'a system note' do
+      let(:action) { 'time_tracking' }
+    end
 
     context 'with a time estimate' do
       it 'sets the note text' do
@@ -836,7 +840,9 @@ describe SystemNoteService, services: true do
       described_class.change_time_spent(noteable, project, author)
     end
 
-    it_behaves_like 'a system note'
+    it_behaves_like 'a system note' do
+      let(:action) { 'time_tracking' }
+    end
 
     context 'when time was added' do
       it 'sets the note text' do