Remove usesExposed and displaysExposed

Closes #3403750

src/Plugin/views/display/ViewsBlockOverride.php

@@ -444,20 +444,6 @@ class ViewsBlockOverride extends Block {
     return parent::execute();
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function usesExposed() {
-    return TRUE;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function displaysExposed() {
-    return FALSE;
-  }
-
   /**
    * Provide the default form for setting options.
    */