Implements hook_install().
function system_install() {
// Enable and set the default theme. Can't use theme_enable() this early in
// installation.
config_install_default_config('theme', 'stark');
config('system.theme')
->set('default', 'stark')
->save();
// Populate the cron key state variable.
$cron_key = Crypt::randomStringHashed(55);
Drupal::state()
->set('system.cron_key', $cron_key);
}