chore(PubSub): Adding GCPServiceAccount and AWSRoleArn class variables to pubsubTest

Author: cy-yun

pubsub/api/test/pubsubTest.php

@@ -17,6 +17,7 @@
 
 namespace Google\Cloud\Samples\PubSub;
 
+use Google\Cloud\Core\Exception\ServiceException;
 use Google\Cloud\TestUtils\TestTrait;
 use Google\Cloud\TestUtils\ExecuteCommandTrait;
 use Google\Cloud\TestUtils\EventuallyConsistentTestTrait;
@@ -32,10 +33,14 @@ class PubSubTest extends TestCase
     use EventuallyConsistentTestTrait;
 
     private static $eodSubscriptionId;
+    private static $awsRoleArn = 'arn:aws:iam::111111111111:role/fake-role-name';
+    private static $gcpServiceAccount;
 
     public static function setUpBeforeClass(): void
     {
         self::$eodSubscriptionId = 'test-eod-subscription-' . rand();
+        $json = file_get_contents(self::requireEnv('GOOGLE_APPLICATION_CREDENTIALS'));
+        self::$gcpServiceAccount = json_decode($json, true)['client_email'];
     }
 
     public function testSubscriptionPolicy()