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/trigger.hpp b/redfish-core/lib/trigger.hpp
index 5e2f050..811d355 100644
--- a/redfish-core/lib/trigger.hpp
+++ b/redfish-core/lib/trigger.hpp
@@ -100,13 +100,12 @@
         {
             return std::nullopt;
         }
-
-        triggers.push_back({
-            {"Name", name},
-            {"Severity", severity},
-            {"DwellTime", *duration},
-            {"Value", value},
-        });
+        nlohmann::json::object_t trigger;
+        trigger["Name"] = name;
+        trigger["Severity"] = severity;
+        trigger["DwellTime"] = *duration;
+        trigger["Value"] = value;
+        triggers.push_back(std::move(trigger));
     }
 
     return {std::move(triggers)};