Migrate ash/constants/ash_switches.* to namespace ash

This CL is part of the Chrome OS source code directory migration:
https://docs.google.com/document/d/1g-98HpzA8XcoGBWUv1gQNr4rbnD5yfvbtYZyPDDbkaE.

Bug: 1157625, 1164001
Change-Id: Ia253571e495128dd9f571af94ced86ec2d1d3354
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3394954
Reviewed-by: Hidehiko Abe <[email protected]>
Owners-Override: Hidehiko Abe <[email protected]>
Commit-Queue: Henrique Ferreiro <[email protected]>
Cr-Commit-Position: refs/heads/main@{#960408}
diff --git a/chrome/browser/ui/webui/help/help_utils_chromeos.cc b/chrome/browser/ui/webui/help/help_utils_chromeos.cc
index 81003fd..baeb212 100644
--- a/chrome/browser/ui/webui/help/help_utils_chromeos.cc
+++ b/chrome/browser/ui/webui/help/help_utils_chromeos.cc
@@ -20,7 +20,7 @@
   // If this is a Cellular First device or the user actively checks for update,
   // the default is to allow updates over cellular.
   bool default_update_over_cellular_allowed =
-      interactive ? true : chromeos::switches::IsCellularFirstDevice();
+      interactive ? true : ash::switches::IsCellularFirstDevice();
 
   // Device Policy overrides the defaults.
   ash::CrosSettings* settings = ash::CrosSettings::Get();