kiosk: Add kiosk.always_update manifest key

chrome/browser/chromeos/app_mode/kiosk_app_manager.cc

Index: chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
index a24c7bf33832508375b2504659ab5c9358568448..44b31160ebe7b38af82ab7c562c5c47f8ac4fe6a 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
@@ -653,6 +653,10 @@ bool KioskAppManager::IsPlatformCompliantWithApp(
   if (info == nullptr)
     return true;
 
+  // Compliant if the app wants to be always updated.
+  if (info->always_update)
+    return true;
+
   return IsPlatformCompliant(info->required_platform_version);
 }