Remove EE-specific lines from SystemNoteHelper

app/helpers/system_note_helper.rb

@@ -22,10 +22,6 @@ module SystemNoteHelper
     'moved' => 'arrow-right',
     'outdated' => 'pencil-square',
     'duplicate' => 'issue-duplicate',
-    'approved' => 'approval',
-    'unapproved' => 'unapproval',
-    'relate' => 'link',
-    'unrelate' => 'unlink',
     'locked' => 'lock',
     'unlocked' => 'lock-open'
   }.freeze

ee/app/helpers/ee/system_note_helper.rb

@@ -3,6 +3,10 @@ module EE
     extend ::Gitlab::Utils::Override
 
     EE_ICON_NAMES_BY_ACTION = {
+      'approved' => 'approval',
+      'unapproved' => 'unapproval',
+      'relate' => 'link',
+      'unrelate' => 'unlink',
       'epic_issue_added' => 'issues',
       'epic_issue_removed' => 'issues',
       'epic_issue_moved' => 'issues',