Update EventCode property to include default value and null handling

Author: cpfk

Source/FikaAmazonAPI/AmazonSpApiSDK/Models/ShippingV2/Event.cs

@@ -18,8 +18,8 @@ public partial class Event : IEquatable<Event>, IValidatableObject
     /// <summary>
     /// Gets or Sets EventCode
     /// </summary>
-    [DataMember(Name = "eventCode", EmitDefaultValue = false)]
-    [JsonProperty(PropertyName = "eventCode")]
+    [DataMember(Name = "eventCode", EmitDefaultValue = true)]
+    [JsonProperty(PropertyName = "eventCode", NullValueHandling = NullValueHandling.Include)]
     public EventCode EventCode { get; set; }
 
     /// <summary>