Add Files app extension id to whitelist on feedback logs

Currently is hard to debug Files app feedback report because Files app
URL is redacted from logs, the URL is similar to:
chrome-extension://$EXTENSIO_ID/.

Bug: 979779
Change-Id: If08ddae7625c431bfe6ca67ac3dd257f14e8410f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2011581
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733850}

chrome/common/extensions/extension_constants.cc

@@ -2,9 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "chrome/common/extensions/extension_constants.h"
+
 #include "base/macros.h"
 #include "build/build_config.h"
-#include "chrome/common/extensions/extension_constants.h"
+#include "extensions/common/constants.h"
 
 namespace extension_urls {
 
@@ -77,6 +79,7 @@ const char* const kBuiltInFirstPartyExtensionIds[] = {
     kAutoclickExtensionId,
     kSelectToSpeakExtensionId,
     kSwitchAccessExtensionId,
+    kFilesManagerAppId,
     kFirstRunDialogId,
     kEspeakSpeechSynthesisExtensionId,
     kGoogleSpeechSynthesisExtensionId,