Telemetry with Parallel and DataCollector Enabled (#1195)

Telemetry was not coming for testhost when DataCollectors with parallel enabled was there

src/Microsoft.TestPlatform.CrossPlatEngine/DataCollection/ParallelDataCollectionEventsHandler.cs

@@ -82,6 +82,9 @@ public override void HandleTestRunComplete(
                     this.runDataAggregator.RunContextAttachments,
                     this.runDataAggregator.ElapsedTime);
 
+                // Add Metrics from Test Host
+                completedArgs.Metrics = this.runDataAggregator.GetAggregatedRunDataMetrics();
+
                 HandleParallelTestRunComplete(completedArgs);
             }
         }