Merge pull request #24086 from HannahShiSFB/fix-unit-tests-slow

PHP: add server->start() to correspond with PR23636

src/php/tests/unit_tests/CallTest.php

@@ -25,6 +25,7 @@ class CallTest extends PHPUnit_Framework_TestCase
     {
         self::$server = new Grpc\Server([]);
         self::$port = self::$server->addHttp2Port('0.0.0.0:53000');
+        self::$server->start();
     }
 
     public function setUp()

src/php/tests/unit_tests/PersistentChannelTests/PersistentChannelTest.php

@@ -180,6 +180,7 @@ class PersistentListTest extends PHPUnit_Framework_TestCase
       $this->channel2 = new Grpc\Channel('localhost:10001', []);
       $this->server = new Grpc\Server([]);
       $this->port = $this->server->addHttp2Port('localhost:10001');
+      $this->server->start();
 
       // channel2 can still be use
       $state = $this->channel2->getConnectivityState();