Fix Warning 'CS4014' in "UITests.App" project

The `SendLogMessage` method in the App class returns `Task` but
we didn't await where it is called, i.e. in the `LogMessage` method.
Thus, updating the method with async/await pattern fixes the warning.

Author: Nirmal4G

UITests/UITests.App/App.AppService.xaml.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Threading.Tasks;
 using Microsoft.Toolkit.Mvvm.Messaging;
 using UITests.App.Pages;
@@ -139,9 +140,10 @@ public async Task SendLogMessage(string level, string msg)
                 { "Message", msg }
             };
 
-            await _appServiceConnection.SendMessageAsync(message);
+            var response = await _appServiceConnection.SendMessageAsync(message);
 
             // TODO: do we care if we have a problem here?
+            Debug.WriteLine(response);
         }
 
         private static bool TryGetValueAndLog(ValueSet message, string key, out string value)
@@ -164,7 +166,7 @@ private static bool TryGetValueAndLog(ValueSet message, string key, out string v
             return true;
         }
 
-        private Dictionary<string, Func<ValueSet, Task<ValueSet>>> _customCommands = new();
+        private readonly Dictionary<string, Func<ValueSet, Task<ValueSet>>> _customCommands = new();
 
         internal void RegisterCustomCommand(string id, Func<ValueSet, Task<ValueSet>> customCommandFunction)
         {

UITests/UITests.App/TestInterop.cs

@@ -28,7 +28,7 @@ public static void Error(string format, params object[] args)
             LogMessage("Error", "[Error] " + format, args);
         }
 
-        private static void LogMessage(string level, string format, object[] args)
+        private static async void LogMessage(string level, string format, object[] args)
         {
             // string.Format() complains if we pass it something with braces, even if we have no arguments.
             // To account for that, we'll escape braces if we have no arguments.
@@ -43,7 +43,7 @@ private static void LogMessage(string level, string format, object[] args)
 
             // Send back to Test Harness via AppService
             // TODO: Make this a cleaner connection/pattern
-            _ = ((App)Application.Current).SendLogMessage(level, message);
+            await ((App)Application.Current).SendLogMessage(level, message).ConfigureAwait(false);
         }
     }
 }