Remove nlohmann brace initialization

There's a few last places (outside of tests) where we still use
nlohmann brace initialization.  Per the transforms we've been doing,
move these to constructing the objects explicitly, using operator[],
nlohmann::object_t and nlohmann::array_t.  Theses were found by manual
inspection grepping for all uses of nlohmann::json.

This is done to reduce binary size and reduce the number of intermediate
objects being constructed.  This commit saves a trivial amount of size
(~4KB, Half a percent of total) and in addition but makes our
construction consistent.

Tested:
Redfish service validator passes.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I7478479a9fdc41b254eef325002d413c1fb411a0
diff --git a/redfish-core/lib/certificate_service.hpp b/redfish-core/lib/certificate_service.hpp
index ebd9436..d3aedd0 100644
--- a/redfish-core/lib/certificate_service.hpp
+++ b/redfish-core/lib/certificate_service.hpp
@@ -78,15 +78,16 @@
             asyncResp->res.jsonValue["CertificateLocations"]["@odata.id"] =
                 "/redfish/v1/CertificateService/CertificateLocations";
         }
-        asyncResp->res
-            .jsonValue["Actions"]["#CertificateService.ReplaceCertificate"] = {
-            {"target",
-             "/redfish/v1/CertificateService/Actions/CertificateService.ReplaceCertificate"},
-            {"CertificateType@Redfish.AllowableValues", {"PEM"}}};
-        asyncResp->res
-            .jsonValue["Actions"]["#CertificateService.GenerateCSR"] = {
-            {"target",
-             "/redfish/v1/CertificateService/Actions/CertificateService.GenerateCSR"}};
+        nlohmann::json& actions = asyncResp->res.jsonValue["Actions"];
+        nlohmann::json& replace =
+            actions["#CertificateService.ReplaceCertificate"];
+        replace["target"] =
+            "/redfish/v1/CertificateService/Actions/CertificateService.ReplaceCertificate";
+        nlohmann::json::array_t allowed;
+        allowed.push_back("PEM");
+        replace["CertificateType@Redfish.AllowableValues"] = std::move(allowed);
+        actions["#CertificateService.GenerateCSR"]["target"] =
+            "/redfish/v1/CertificateService/Actions/CertificateService.GenerateCSR";
         });
 } // requestRoutesCertificateService