Empty value $config->get('enabled_entity_types') AND $config->get('safe_tokens')

TypeError: in_array(): Argument #2 ($haystack) must be of type array, null given in in_array() (line 152 of modules/contrib/pathauto/src/Form/PathautoSettingsForm.php).

in_array('block_content', NULL) (Line: 152)
Drupal\pathauto\Form\PathautoSettingsForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 531)
Drupal\Core\Form\FormBuilder->retrieveForm('pathauto_settings_form', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 564)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 158)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

TypeError: implode(): Argument #1 ($pieces) must be of type array, string given in implode() (line 254 of modules/contrib/pathauto/src/Form/PathautoSettingsForm.php).

The website encountered an unexpected error. Please try again later.
TypeError: implode(): Argument #1 ($pieces) must be of type array, string given in implode() (line 254 of modules/contrib/pathauto/src/Form/PathautoSettingsForm.php).
implode(', ', NULL) (Line: 254)
Drupal\pathauto\Form\PathautoSettingsForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 531)
Drupal\Core\Form\FormBuilder->retrieveForm('pathauto_settings_form', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 564)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 158)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce

1. Install an empty drupal 9
2. go to http://localhost/admin/config/search/path/settings

Proposed resolution

Check the default $config->get('enabled_entity_types') value if array

$form['enabled_entity_types'][$entity_type_id] = [
          '#type' => 'checkbox',
          '#title' => $entity_type->getLabel(),
          '#default_value' => isset($field_definitions['path']) || (is_array($config->get('enabled_entity_types')) ? in_array($entity_type_id, $config->get('enabled_entity_types')) : FALSE),
          '#disabled' => isset($field_definitions['path']) && ($field_definitions['path']->getProvider() != 'pathauto' || $patterns_count),
        ];

Check the default $config->get('safe_tokens') value if not empty

 $form['safe_tokens'] = [
      '#type' => 'textarea',
      '#title' => $this->t('Safe tokens'),
      '#default_value' => !empty($config->get('safe_tokens')) ? implode(', ', $config->get('safe_tokens')) : '',
      '#description' => $this->t('List of tokens that are safe to use in alias patterns and do not need to be cleaned. For example urls, aliases, machine names. Separated with a comma.'),
    ];

Data model changes