Add hasOverrides method

Closes #2983999

src/UnsavedIndexConfiguration.php

@@ -1152,4 +1152,11 @@ class UnsavedIndexConfiguration implements IndexInterface, UnsavedConfigurationI
     return $this->entity->getThirdPartyProviders();
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function hasOverrides(): bool {
+    return $this->entity->hasOverrides();
+  }
+
 }