minor #19512 [HttpKernel] Fix variable conflicting name (tgalopin)

This PR was merged into the 2.7 branch.

Discussion
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[HttpKernel] Fix variable conflicting name

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Simply fix a conflicting name (`$bundle` is used for the foreach on line 466 and 476). It works for the moment only because there is nothing after the second foreach inside the first.

Commits
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9ac9f55 [HttpKernel] Fix variable conflicting name

Author: nicolas-grekas

Kernel.php

@@ -465,8 +465,8 @@ protected function initializeBundles()
                 $hierarchy[] = $name;
             }
 
-            foreach ($hierarchy as $bundle) {
-                $this->bundleMap[$bundle] = $bundleMap;
+            foreach ($hierarchy as $hierarchyBundle) {
+                $this->bundleMap[$hierarchyBundle] = $bundleMap;
                 array_pop($bundleMap);
             }
         }