opencase/modules/opencase_entities/opencase_entities.install

<?php

// Change date formats on created and changed dates.
function opencase_entities_update_801910() {
  $update_manager = \Drupal::entityDefinitionUpdateManager();
  $field = $update_manager->getFieldStorageDefinition('created', 'oc_case');
  $properties = array(
    'targetEntityType' => $field->getTargetEntityTypeId(),
    'bundle' => $field->getTargetBundle()
  );
  if ($view_displays = \Drupal::entityTypeManager()->getStorage('entity_view_display')->loadByProperties($properties)) {
    foreach ($view_displays as $view_display) {
      $view_display->setComponent('created', array(
        'type' => 'datetime_default',
        'settings' => ['format_type' => 'short'],
      ) + $component)->save();
    }
  }
}

// Make contact details revisionable.
function opencase_entities_update_80191() {
  $update_manager = \Drupal::entityDefinitionUpdateManager();
  $contact_details_fields = ['email', 'phone', 'phone2', 'postal_address', 'post_code'];
  foreach($contact_details_fields as $field) {
    $definition = $update_manager->getFieldStorageDefinition($field, 'oc_actor');
    $definition->setRevisionable(TRUE);
  }
}

use \Drupal\Core\Entity\Sql\SqlContentEntityStorageSchemaConverter;

/**
 * Update my_entity to be revisionable.
 */
function opencase_entities_update_8019(&$sandbox) {
  $schema_converter = new SqlContentEntityStorageSchemaConverter(
    'oc_actor',
    \Drupal::entityTypeManager(),
    \Drupal::entityDefinitionUpdateManager(),
    \Drupal::service('entity.last_installed_schema.repository'),
    \Drupal::keyValue('entity.storage_schema.sql'),
    \Drupal::database()
  );

  $contact_details_fields = ['email', 'phone', 'phone2', 'postal_address', 'post_code'];
  $schema_converter->convertToRevisionable($sandbox, $contact_details_fields);
}

// Make contact details revisionable.
function opencase_entities_update_8018() {
  $update_manager = \Drupal::entityDefinitionUpdateManager();
  $contact_details_fields = ['email', 'phone', 'phone2', 'postal_address', 'post_code'];
  foreach($contact_details_fields as $field) {
    $definition = $update_manager->getFieldStorageDefinition($field, 'oc_actor');
    $update_manager->updateFieldStorageDefinition($definition);
  }
}

function opencase_entities_update_8016() {
  $update_manager = \Drupal::entityDefinitionUpdateManager();
  $definition = $update_manager->getFieldStorageDefinition('activity_date_time', 'oc_activity');
  $update_manager->updateFieldStorageDefinition($definition);
}

/**
 * Add 'activity_date_time' field to 'oc_activity' entities.
 */
function opencase_entities_update_8003() {
  $storage_definition =  \Drupal\Core\Field\BaseFieldDefinition::create('datetime')
      ->setLabel(t('Date and time'))
      ->setRevisionable(TRUE)
      ->setDefaultValueCallback('\Drupal\opencase_entities\Entity\OCActivity::currentDateTime')
      ->setDisplayOptions('view', [
        'type' => 'datetime_default',
        'settings' => [
          'format_type' => 'medium',
        ],
        'label' => 'above',
        'weight' => -3,
      ])
      ->setDisplayOptions('form', [
        'type' => 'datetime_default',
        'weight' => -3,
      ]);

  \Drupal::entityDefinitionUpdateManager()
    ->installFieldStorageDefinition('activity_date_time', 'oc_activity', 'oc_activity', $storage_definition);
}