drupal/core/modules/migrate_drupal/migrate_drupal.install

<?php

/**
 * @file
 * Contains install and update functions for Migrate Drupal
 */

/**
 * Creates migrate_drupal.settings config object.
 */
function migrate_drupal_update_8501() {
  \Drupal::configFactory()
    ->getEditable('migrate_drupal.settings')
    ->set('enforce_source_module_tags', ['Drupal 6', 'Drupal 7'])
    ->save();
}

/**
 * Sets the follow-up migration tags.
 */
function migrate_drupal_update_8502() {
  \Drupal::configFactory()
    ->getEditable('migrate_drupal.settings')
    ->set('follow_up_migration_tags', ['Follow-up migration'])
    ->save();
}

/**
 * Install migrate_drupal_multilingual since migrate_drupal is installed.
 */
function migrate_drupal_update_8601() {
  \Drupal::service('module_installer')->install(['migrate_drupal_multilingual']);
}