Extract EE code from Admin::HealthCheckController

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/controllers/admin/health_check_controller.rb

@@ -2,9 +2,14 @@
 
 class Admin::HealthCheckController < Admin::ApplicationController
   def show
-    checks = ['standard']
-    checks << 'geo' if Gitlab::Geo.secondary?
-
     @errors = HealthCheck::Utils.process_checks(checks)
   end
+
+  private
+
+  def checks
+    ['standard']
+  end
 end
+
+Admin::HealthCheckController.prepend(EE::Admin::HealthCheckController)

ee/app/controllers/ee/admin/health_check_controller.rb

+# frozen_string_literal: true
+
+module EE
+  module Admin
+    module HealthCheckController
+      extend ::Gitlab::Utils::Override
+      include ::Gitlab::Utils::StrongMemoize
+
+      private
+
+      override :checks
+      def checks
+        strong_memoize(:checks) do
+          base_checks = super
+          base_checks << 'geo' if ::Gitlab::Geo.secondary?
+
+          base_checks
+        end
+      end
+    end
+  end
+end