Bug fix: handle the case where a container has only default elements

Code/Framework/AzCore/AzCore/Serialization/Json/BasicContainerSerializer.cpp

@@ -102,6 +102,17 @@ namespace AZ
             return context.Report(retVal, "Processing of basic container was halted.");
         }
 
+        // If each container element was 'DefaultsUsed', then the result code will be 'DefaultsUsed'
+        // But this is wrong if the container has at least one element, because a container with
+        // at least one element is certainly not the default container value.
+        // Basically, the following are different objects:
+        //   [ {} ]       // The container which has only default elements, but is not the empty container
+        //   {}           // The default container, which is empty
+        if (index > 0)
+        {
+            retVal.Combine(JSR::ResultCode(JSR::Tasks::WriteValue, JSR::Outcomes::Success));
+        }
+
         if (context.ShouldKeepDefaults())
         {
             outputValue = AZStd::move(array);