farm-2.x-dev/modules/core/ui/dashboard/farm_ui_dashboard.install

<?php

/**
 * @file
 * Install, update and uninstall functions for the farm_ui_dashboard module.
 */

/**
 * Implements hook_install().
 */
function farm_ui_dashboard_install() {

  // Set the front page to /dashboard.
  \Drupal::configFactory()->getEditable('system.site')->set('page.front', '/dashboard')->save();
}