[10.x] Retain $request->request InputBag type

[timacdonald]

When we create the Illuminate request, we set the $request->request property to the value of the $request->json property.

Symfony is expecting $request->request to be an InputBag when invoking $request->getPayload(). See:

https://github.com/symfony/symfony/blob/42d9d7cd64c5b9897a2113c12d76c75a8d31ad9c/src/Symfony/Component/HttpFoundation/Request.php#L1514

The $request->json property is an instance of ParameterBag. This is the parent class of InputBag.

So we are setting $request->request to an instance of ParameterBag instead of InputBag which is then breaking due to the return type on Request::getPayload()

Side note

It is possible that we should make $request->json an instance of InputBag to make things consistent, however this is a quick fix to fix the framework asap.

fixes #47834

[LukeTowers]

Can this get back-ported to the 9.x branch as well?

[timacdonald]

See: #47840