add runtime config file

Author: GarrettBeatty

Tools/LambdaTestTool-v2/tests/Amazon.Lambda.TestTool.UnitTests/PackagingTests.cs

@@ -115,7 +115,8 @@ public void VerifyPackageContentsHasRuntimeSupport()
             {
                 $"content/Amazon.Lambda.RuntimeSupport/{framework}/Amazon.Lambda.Core.dll",
                 $"content/Amazon.Lambda.RuntimeSupport/{framework}/Amazon.Lambda.RuntimeSupport.dll",
-                $"content/Amazon.Lambda.RuntimeSupport/{framework}/Amazon.Lambda.RuntimeSupport.deps.json"
+                $"content/Amazon.Lambda.RuntimeSupport/{framework}/Amazon.Lambda.RuntimeSupport.deps.json",
+                $"content/Amazon.Lambda.RuntimeSupport/{framework}/Amazon.Lambda.RuntimeSupport.runtimeconfig.json"
             };
 
             var missingFiles = essentialFiles.Where(f => !frameworkFiles.Contains(f)).ToList();