Add log content for PAIYarnTrainingService (#2409)

src/nni_manager/training_service/pai/paiYarn/paiYarnTrainingService.ts

@@ -283,6 +283,9 @@ class PAIYarnTrainingService extends PAITrainingService {
         };
         request(submitJobRequest, (error: Error, response: request.Response, _body: any) => {
             if ((error !== undefined && error !== null) || response.statusCode >= 400) {
+                const errorMessage: string = (error !== undefined && error !== null) ? error.message : 
+                `Submit trial ${trialJobId} failed, http code:${response.statusCode}, http body: ${response.body.message}`;
+                this.log.error(errorMessage);
                 trialJobDetail.status = 'FAILED';
                 deferred.resolve(true);
             } else {