unify main and appOutputLog for MacCatalyst

Author: matouskozak

src/Microsoft.DotNet.XHarness.Apple/AppOperations/AppRunnerBase.cs

@@ -101,14 +101,18 @@ protected async Task<ProcessExecutionResult> RunMacCatalystApp(
 
         var logStreamScanToken = CaptureMacCatalystLog(appInformation, cancellationToken);
 
+        // The app output log is not directly accessible. 
+        // Hence, we duplicate the log to the main console log to simplify the UX of failure investigation.
+        IFileBackedLog aggregatedAppOutputLog = Log.CreateReadableAggregatedLog(_mainLog, appOutputLog);
+
         try
         {
             return await _processManager.ExecuteCommandAsync(
                 "open",
                 arguments,
                 _mainLog,
-                appOutputLog,
-                appOutputLog,
+                aggregatedAppOutputLog,
+                aggregatedAppOutputLog,
                 timeout,
                 environmentVariables,
                 cancellationToken);