minor #18404 [HttpFoundation] fix phpdoc of UploadedFile (Tobion)

This PR was merged into the 2.3 branch.

Discussion
----------

[HttpFoundation] fix phpdoc of UploadedFile

| Q             | A
| ------------- | ---
| Branch?       | 2.3
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Commits
-------

cbcac56 [HttpFoundation] fix phpdoc of UploadedFile

src/Symfony/Component/HttpFoundation/File/UploadedFile.php

@@ -50,7 +50,7 @@ class UploadedFile extends File
     /**
      * The file size provided by the uploader.
      *
-     * @var string
+     * @var int|null
      */
     private $size;
 
@@ -75,12 +75,12 @@ class UploadedFile extends File
      *
      * Calling any other method on an non-valid instance will cause an unpredictable result.
      *
-     * @param string $path         The full temporary path to the file
-     * @param string $originalName The original file name
-     * @param string $mimeType     The type of the file as provided by PHP
-     * @param int    $size         The file size
-     * @param int    $error        The error constant of the upload (one of PHP's UPLOAD_ERR_XXX constants)
-     * @param bool   $test         Whether the test mode is active
+     * @param string      $path         The full temporary path to the file
+     * @param string      $originalName The original file name
+     * @param string|null $mimeType     The type of the file as provided by PHP; null defaults to application/octet-stream
+     * @param int|null    $size         The file size
+     * @param int|null    $error        The error constant of the upload (one of PHP's UPLOAD_ERR_XXX constants); null defaults to UPLOAD_ERR_OK
+     * @param bool        $test         Whether the test mode is active
      *
      * @throws FileException         If file_uploads is disabled
      * @throws FileNotFoundException If the file does not exist