FeedForm incorrectly extends ContentEntityForm

When using feeds on a Drupal 8.3.x installation it isn't possible to create new feeds due to the following error:

The website encountered an unexpected error. Please try again later.
Error: Call to a member function getRequestTime() on null in Drupal\Core\Entity\ContentEntityForm->updateChangedTime() (line 373 of core/lib/Drupal/Core/Entity/ContentEntityForm.php).
Drupal\Core\Entity\ContentEntityForm->updateChangedTime(Object) (Line: 139)
Drupal\Core\Entity\ContentEntityForm->submitForm(Array, Object) (Line: 174)
Drupal\feeds\FeedForm->submitForm(Array, Object)
call_user_func_array(Array, Array) (Line: 111)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object) (Line: 51)
Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object) (Line: 585)
Drupal\Core\Form\FormBuilder->processForm('feeds_feed_rechtspraak_nl_form', Array, Object) (Line: 314)
Drupal\Core\Form\FormBuilder->buildForm('feeds_feed_rechtspraak_nl_form', Object) (Line: 74)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 574)
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}()
call_user_func_array(Object, Array) (Line: 144)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

This issue exists due to this change in Drupal core. Which changes the $entity->setChangedTime(REQUEST_TIME); call in updateChangedTime (in the ContentEntityForm), to $entity->setChangedTime($this->time->getRequestTime()); and $this->time is never set from the feed form.