Add system checks to dashboard in admin UI (#15989)

app/lib/admin/system_check/rules_check.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class Admin::SystemCheck::RulesCheck < Admin::SystemCheck::BaseCheck
+  include RoutingHelper
+
+  def pass?
+    Rule.kept.exists?
+  end
+
+  def message
+    Admin::SystemCheck::Message.new(:rules_check, nil, admin_rules_path)
+  end
+end