UserManager: set user.supervisedUser only for legacy supervised users

Since https://codereview.chromium.org/899663003, child accounts would get both the "supervised user" and the "child" icons. This CL fixes that.

Review URL: https://codereview.chromium.org/897903002

Cr-Commit-Position: refs/heads/master@{#314573}

chrome/browser/ui/webui/signin/user_manager_screen_handler.cc

@@ -728,7 +728,7 @@ void UserManagerScreenHandler::SendUserList() {
         kKeyProfilePath, base::CreateFilePathValue(profile_path));
     profile_value->SetBoolean(kKeyPublicAccount, false);
     profile_value->SetBoolean(
-        kKeySupervisedUser, info_cache.ProfileIsSupervisedAtIndex(i));
+        kKeySupervisedUser, info_cache.ProfileIsLegacySupervisedAtIndex(i));
     profile_value->SetBoolean(
         kKeyChildUser, info_cache.ProfileIsChildAtIndex(i));
     profile_value->SetBoolean(