Issue#17 Logic using route cutsomizations for async api routes. Needed config was moved to webapi_async.xml.

Author: Pavel

app/code/Magento/WebapiAsync/Model/RouteCustomizationConfig.php

@@ -20,7 +20,7 @@
  */
 class ServiceConfig
 {
-    const CACHE_ID = 'webapi_async_config';
+    const CACHE_ID = 'webapi_async_service_config';
 
     /**
      * @var WebapiCache
@@ -71,7 +71,7 @@ public function getServices()
             if ($services && is_string($services)) {
                 $this->services = $this->serializer->unserialize($services);
             } else {
-                $this->services = $this->configReader->read()[Converter::KEY_SERVICES] ?? [];
+                $this->services = $this->configReader->read();
                 $this->cache->save($this->serializer->serialize($this->services), self::CACHE_ID);
             }
         }