MC-35985: Enable new consumer configuration settings on current consumers

- Update handling onlySpawnWhenMessageAvailable attribute;

Author: adifucan

app/code/Magento/MessageQueue/Model/Cron/ConsumersRunner.php

@@ -176,11 +176,12 @@ private function canBeRun(ConsumerConfigItemInterface $consumerConfig, array $al
             return false;
         }
 
-        $onlySpawnWhenMessageAvailable = (bool)$this->deploymentConfig->get(
+        $globalOnlySpawnWhenMessageAvailable = (bool)$this->deploymentConfig->get(
             'queue/only_spawn_when_message_available',
-            0
+            true
         );
-        if ($onlySpawnWhenMessageAvailable || $consumerConfig->getOnlySpawnWhenMessageAvailable()) {
+        if ($consumerConfig->getOnlySpawnWhenMessageAvailable() === true
+            || ($consumerConfig->getOnlySpawnWhenMessageAvailable() === null && $globalOnlySpawnWhenMessageAvailable)) {
             try {
                 return $this->checkIsAvailableMessages->execute(
                     $connectionName,

lib/internal/Magento/Framework/MessageQueue/Config/Consumer/ConfigReaderPlugin.php

@@ -71,7 +71,7 @@ private function getConsumerConfigDataFromQueueConfig()
                 'maxMessages' => $consumerData['max_messages'],
                 'maxIdleTime' => null,
                 'sleep' => null,
-                'onlySpawnWhenMessageAvailable' => false
+                'onlySpawnWhenMessageAvailable' => null
             ];
         }
 

lib/internal/Magento/Framework/MessageQueue/Consumer/Config/Xml/Converter.php

@@ -77,7 +77,7 @@ public function convert($source)
                 'maxIdleTime' => $this->getAttributeValue($consumerNode, 'maxIdleTime'),
                 'sleep' => $this->getAttributeValue($consumerNode, 'sleep'),
                 'onlySpawnWhenMessageAvailable' =>
-                    $onlySpawnWhenMessageAvailable === 'false' ? false : boolval($onlySpawnWhenMessageAvailable)
+                    $onlySpawnWhenMessageAvailable === null ? null : boolval($onlySpawnWhenMessageAvailable)
             ];
         }
         return $result;