minor #40973 [HttpFoundation] Small phpdoc improvement (flack)

This PR was merged into the 4.4 branch.

Discussion
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[HttpFoundation] Small phpdoc improvement

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       |
| License       | MIT
| Doc PR        |

I have been looking for a way to emulate `$_REQUEST` in Symfony, and I always thought the `get` method is useless for that, because it only looks at some custom routing stuff, GET and whatever BODY might be. Only today I actually looked at the source code and found out that it's actually (almost) doing what I was looking for, i.e. check `$_GET`, and then `$_POST`. So I figured it would be good to be a bit more explicit in the phpdoc (analoguous to the phpdoc for `$request->request`, which says "Request body parameters ($_POST).").

Commits
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a53f256b4b Small phpdoc imporvement

Author: fabpot

Request.php

@@ -686,7 +686,7 @@ public static function getHttpMethodParameterOverride()
      * flexibility in controllers, it is better to explicitly get request parameters from the appropriate
      * public property instead (attributes, query, request).
      *
-     * Order of precedence: PATH (routing placeholders or custom attributes), GET, BODY
+     * Order of precedence: PATH (routing placeholders or custom attributes), GET, POST
      *
      * @param string $key     The key
      * @param mixed  $default The default value if the parameter key does not exist