Set the per test timeout to 15 minutes so we get a dump if there is a hang but don't fail for expected longer tests

Author: marcpopMSFT

test/HelixTasks/SDKCustomCreateXUnitWorkItemsWithTestExclusion.cs

@@ -152,7 +152,7 @@ private async Task<List<ITaskItem>> PrepareWorkItem(ITaskItem xunitProject)
 
                 var testFilter = string.IsNullOrEmpty(assemblyPartitionInfo.ClassListArgumentString) ? "" : $"--filter \"{assemblyPartitionInfo.ClassListArgumentString}\"";
                 command = $"{driver} test {assemblyName} -e HELIX_WORK_ITEM_TIMEOUT={timeout} {testExecutionDirectory} {msbuildAdditionalSdkResolverFolder} " +
-                            $"{(XUnitArguments != null ? " " + XUnitArguments : "")} --results-directory .{Path.DirectorySeparatorChar} --logger trx --blame-hang --blame-hang-timeout 1m {testFilter} -- {arguments}";
+                            $"{(XUnitArguments != null ? " " + XUnitArguments : "")} --results-directory .{Path.DirectorySeparatorChar} --logger trx --blame-hang --blame-hang-timeout 15m {testFilter} -- {arguments}";
 
                 Log.LogMessage($"Creating work item with properties Identity: {assemblyName}, PayloadDirectory: {publishDirectory}, Command: {command}");