Issue #3489123 by grimreaper, mogtofu33: Icon not found when rendered from renderable array

Closes #3489123

modules/ui_icons_backport/src/Element/Icon.php

@@ -60,10 +60,8 @@ class Icon extends RenderElementBase {
   public static function preRenderIcon(array $element): array {
     $icon_full_id = IconDefinition::createIconId($element['#pack_id'], $element['#icon_id']);
 
-    $iconCollector = \Drupal::service('Drupal\Core\Theme\Icon\IconCollector');
-    $icon = $iconCollector->get($icon_full_id);
-
-    if (!$icon) {
+    $pluginManagerIconPack = \Drupal::service('plugin.manager.icon_pack');
+    if (!$icon = $pluginManagerIconPack->getIcon($icon_full_id)) {
       return $element;
     }