.Net: Test with the LightPlugin (microsoft#7285)

### Motivation and Context

Update sample to match issue microsoft#7268 

### Description

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

---------

Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com>

dotnet/samples/Concepts/ChatCompletion/OpenAI_FunctionCalling.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System.ComponentModel;
+using System.Text.Json;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.ChatCompletion;
 using Microsoft.SemanticKernel.Connectors.OpenAI;
@@ -67,7 +68,26 @@ public async Task AutoInvokeKernelFunctionsWithComplexParameterAsync()
         Console.WriteLine(chatPromptResult);
     }
 
-    public sealed class WeatherPlugin
+    [Fact]
+    public async Task AutoInvokeLightPluginAsync()
+    {
+        // Create a kernel with OpenAI chat completion and LightPlugin
+        Kernel kernel = CreateKernelWithPlugin<LightPlugin>();
+        kernel.FunctionInvocationFilters.Add(new FunctionFilterExample(this.Output));
+
+        // Invoke chat prompt with auto invocation of functions enabled
+        const string ChatPrompt = """
+            <message role="user">Turn on the light?</message>
+        """;
+        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var chatSemanticFunction = kernel.CreateFunctionFromPrompt(
+            ChatPrompt, executionSettings);
+        var chatPromptResult = await kernel.InvokeAsync(chatSemanticFunction);
+
+        Console.WriteLine(chatPromptResult);
+    }
+
+    private sealed class WeatherPlugin
     {
         [KernelFunction]
         [Description("Get the current weather in a given location.")]
@@ -76,7 +96,7 @@ public string GetWeather(
         ) => $"12°C\nWind: 11 KMPH\nHumidity: 48%\nMostly cloudy\nLocation: {location}";
     }
 
-    public sealed class HolidayPlugin
+    private sealed class HolidayPlugin
     {
         [KernelFunction]
         [Description("Book a holiday for a specified time period.")]
@@ -85,7 +105,7 @@ public string BookHoliday(
         ) => $"Holiday booked, starting {holidayRequest.StartDate} and ending {holidayRequest.EndDate}";
     }
 
-    public sealed class HolidayRequest
+    private sealed class HolidayRequest
     {
         [Description("The date when the holiday period starts in ISO 8601 format")]
         public string StartDate { get; set; } = string.Empty;
@@ -94,6 +114,24 @@ public sealed class HolidayRequest
         public string EndDate { get; set; } = string.Empty;
     }
 
+    private sealed class LightPlugin
+    {
+        public bool IsOn { get; set; } = false;
+
+        [KernelFunction]
+        [Description("Gets the state of the light.")]
+        public string GetState() => IsOn ? "on" : "off";
+
+        [KernelFunction]
+        [Description("Changes the state of the light.'")]
+        public string ChangeState(bool newState)
+        {
+            this.IsOn = newState;
+            var state = GetState();
+            return state;
+        }
+    }
+
     private Kernel CreateKernelWithPlugin<T>()
     {
         // Create a logging handler to output HTTP requests and responses
@@ -110,4 +148,14 @@ private Kernel CreateKernelWithPlugin<T>()
         Kernel kernel = kernelBuilder.Build();
         return kernel;
     }
+
+    private sealed class FunctionFilterExample(ITestOutputHelper output) : IFunctionInvocationFilter
+    {
+        public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
+        {
+            output.WriteLine($"Function {context.Function.Name} is being invoked with arguments: {JsonSerializer.Serialize(context.Arguments)}");
+
+            await next(context);
+        }
+    }
 }