Issue #3276915 by dtfabio, tim-diels: Clean up ActiveCampaignApi service

activecampaign.services.yml

 services:
   activecampaign.api:
     class: Drupal\activecampaign\ActiveCampaignApi
-    arguments: ['@config.storage']
+    arguments: ['@config.factory']

src/ActiveCampaignApi.php

@@ -3,7 +3,7 @@
 namespace Drupal\activecampaign;
 
 use Drupal\Component\Utility\UrlHelper;
-use Drupal\Core\Config\StorageInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Url;
 
 /**
@@ -18,6 +18,13 @@ class ActiveCampaignApi {
    */
   protected $activeCampaignSDK;
 
+  /**
+   * The config factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
   /**
    * The url to active campaign.
    *
@@ -28,11 +35,12 @@ class ActiveCampaignApi {
   /**
    * Constructs an Api object.
    *
-   * @param \Drupal\Core\Config\StorageInterface $storage
-   *   The active configuration storage.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The configuration factory.
    */
-  public function __construct(StorageInterface $storage) {
-    $config = \Drupal::config('activecampaign.settings');
+  public function __construct(ConfigFactoryInterface $config_factory) {
+    $this->configFactory = $config_factory;
+    $config = $this->configFactory->get('activecampaign.settings');
     $this->url = $config->get('url');
     $this->activeCampaignSDK = new \ActiveCampaign($config->get('api_url'), $config->get('api_key'));
   }