Remove unnecessary #if OS_CHROMEOS from os_settings_ui.cc

The file is only compiled on Chrome OS, so the #if isn't needed.

Bug: none
Change-Id: I6dc128fab4527e12c7d26593922d06143b567343
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2073220
Auto-Submit: James Cook <jamescook@chromium.org>
Commit-Queue: Jeevan Shikaram <jshikaram@chromium.org>
Reviewed-by: Jeevan Shikaram <jshikaram@chromium.org>
Cr-Commit-Position: refs/heads/master@{#744874}

chrome/browser/ui/webui/settings/chromeos/os_settings_ui.cc

@@ -169,11 +169,9 @@ OSSettingsUI::OSSettingsUI(content::WebUI* web_ui)
   html_source->AddBoolean("splitSettingsSyncEnabled",
                           chromeos::features::IsSplitSettingsSyncEnabled());
 
-#if defined(OS_CHROMEOS)
   html_source->AddBoolean(
       "isSupportedArcVersion",
       AppManagementPageHandler::IsCurrentArcVersionSupported(profile));
-#endif  // OS_CHROMEOS
 
   AddSettingsPageUIHandler(
       base::WrapUnique(::settings::AboutHandler::Create(html_source, profile)));