feature #6174 Missing reference docs for kernel.finish_request event (acrobat)

This PR was merged into the 2.7 branch.

Discussion
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Missing reference docs for kernel.finish_request event

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | yes - missing docs (PR symfony/symfony#8904)
| Applies to    | Event was added in 2.4 so added to **2.7** docs
| Fixed tickets | #6151

Commits
-------

aad2b89 Missing reference docs for kernel.finish_request event

Author: xabbuh

reference/events.rst

@@ -158,6 +158,35 @@ Listener Class Name
 :class:`Symfony\\Component\\HttpKernel\\EventListener\\StreamedResponseListener`     -1024
 ===================================================================================  ========
 
+``kernel.finish_request``
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+**Event Class**: :class:`Symfony\\Component\\HttpKernel\\Event\\FinishRequestEvent`
+
+The purpose of this event is to allow you to reset the global and environmental state of
+the application after a sub-request has finished::
+
+    public function onKernelFinishRequest(FinishRequestEvent $event)
+    {
+        if (null === $parentRequest = $this->requestStack->getParentRequest()) {
+            return;
+        }
+
+        //Reset the locale of the subrequest to the locale of the parent request
+        $this->setLocale($parentRequest);
+    }
+
+These are the built-in Symfony listeners related to this event:
+
+==========================================================================  ========
+Listener Class Name                                                         Priority
+==========================================================================  ========
+:class:`Symfony\\Component\\HttpKernel\\EventListener\\LocaleListener`      0
+:class:`Symfony\\Component\\HttpKernel\\EventListener\\TranslatorListener`  0
+:class:`Symfony\\Component\\HttpKernel\\EventListener\\RouterListener`      0
+:class:`Symfony\\Component\\Security\\Http\\Firewall`                       0
+==========================================================================  ========
+
 ``kernel.terminate``
 ~~~~~~~~~~~~~~~~~~~~