rc-1.0.x-dev/rc.install

<?php

use Drupal\field\Entity\FieldStorageConfig;
use Drupal\field\Entity\FieldConfig;

/**
 * Implements hook_uninstall().
 *
 * @throws \Drupal\Core\Entity\EntityStorageException
 */
function rc_uninstall($is_syncing) {

  // Delete Rocket Chat Account ID and token fields from user entity.
  $fields = ['field_rcid', 'field_rc_token'];

  foreach ($fields as $fieldName) {
    $field = FieldStorageConfig::loadByName('user',$fieldName);

    // Check if field exist.
    if ($field) {
      $field->delete();
    }
  }

  // Delete RC People view.
  $view = \Drupal::service('config.factory')
    ->getEditable('views.view.rc_people');
  if ($view) {
    $view->delete();
  }

}