refactor: refactor code in labels allocation sample

Author: Joanna Grycz

batch/create/create_batch_labels_allocation.js

@@ -117,9 +117,7 @@ async function main() {
   // [END batch_labels_allocation]
 }
 
-process.on('unhandledRejection', err => {
+main().catch(err => {
   console.error(err.message);
   process.exitCode = 1;
 });
-
-main();

batch/test/create_batch_labels_allocation.test.js

@@ -41,7 +41,7 @@ describe('Create batch labels allocation', async () => {
 
   it('should create a new job with allocation policy labels', async () => {
     const expectedAllocationLabels = {
-      'batch-job-id': 'batch-labels-allocation-job',
+      'batch-job-id': jobName,
       vm_label_name_1: 'vmLabelValue1',
       vm_label_name_2: 'vmLabelValue2',
     };