[ECO-4567] Refactored MsgPackHelper config, added comments for unity build

Author: sacOO7

cake-build/tasks/build.cake

@@ -129,6 +129,7 @@ Task("_Build_Ably_Unity_Dll")
     // Get Unity dependency licenses and embed them into primaryDll
     // MergeResources returns the path to the modified DLL (same as input, but ensures file handles are closed)
     var unityLicenseFile = licenseHelper.GetUnityDependencyLicenses();
+    // You can use ILDASM or ILSpy to decode unity/Assets/Ably/Plugins/IO.Ably.dll and check THIRD_PARTY_LICENSES.txt
     var primaryDllWithResources = monoCecilHelper.MergeResources(primaryDll, new FilePath[] { unityLicenseFile });
 
     var dllsToMerge = deps.GetUnityPackageDependencies(netStandard20BinPath);

src/IO.Ably.Shared/MsgPack/MsgPackHelper.cs

@@ -22,13 +22,12 @@ internal static class MsgPackHelper
                 AblyGeneratedResolver.Instance,       // 1. Check generated code first (Fastest/Specific)
                 AblyResolver.Instance,                // 2. Check manual custom resolvers
                 BuiltinResolver.Instance,             // 3. Check standard types (List, DateTime)
-                DynamicGenericResolver.Instance,      // Priority 4: Collections, arrays, tuples
-                PrimitiveObjectResolver.Instance,     // Priority 5: typeof(object) fields
+                DynamicGenericResolver.Instance,      // 4: Check Collections, arrays, tuples
+                PrimitiveObjectResolver.Instance,     // 5: Check typeof(object) fields
         };
 
         private static readonly MessagePackSerializerOptions DefaultOptions = MessagePackSerializerOptions.Standard
-            .WithResolver(CompositeResolver.Create(Resolvers))
-            .WithSecurity(MessagePackSecurity.UntrustedData);
+            .WithResolver(CompositeResolver.Create(Resolvers));
 
         public static byte[] Serialise<T>(T obj, MessagePackSerializerOptions options = null)
         {