Move to common variant

This saves approximately 34kB in the compressed binary size of bmcweb
due to reduced template instantiations.  This amounts to a 2.5%
reduction in the overall size.

Note, there were a few places where we broke const-correctness in the
form of pulling a non-const reference out of a const variant.  This
new variant now requires const correctness, so some consts are
added where required.

Tested: Code compiles.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I6a60c8881c1268627eedb4ffddf16689dc5f6ed2
diff --git a/http/routing.hpp b/http/routing.hpp
index eca1b3a..fe9c7e9 100644
--- a/http/routing.hpp
+++ b/http/routing.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "common.hpp"
+#include "dbus_utility.hpp"
 #include "error_messages.hpp"
 #include "http_request.hpp"
 #include "http_response.hpp"
@@ -1306,12 +1307,10 @@
         }
 
         crow::connections::systemBus->async_method_call(
-            [&req, asyncResp, &rules, ruleIndex, found](
-                const boost::system::error_code ec,
-                const std::map<
-                    std::string,
-                    std::variant<bool, std::string, std::vector<std::string>>>&
-                    userInfo) {
+            [&req, asyncResp, &rules, ruleIndex,
+             found](const boost::system::error_code ec,
+                    const std::map<std::string, dbus::utility::DbusVariantType>&
+                        userInfo) {
                 if (ec)
                 {
                     BMCWEB_LOG_ERROR << "GetUserInfo failed...";