config_service: change error message for error 403.

appengine/config_service/ui/src/config-ui/config-set.html

Index: appengine/config_service/ui/src/config-ui/config-set.html
diff --git a/appengine/config_service/ui/src/config-ui/config-set.html b/appengine/config_service/ui/src/config-ui/config-set.html
index 2b99e1288514be3795f07f9f873b03cd62ebdd4d..f86e64df786a5cdc677bc38035fd40436cd37375 100644
--- a/appengine/config_service/ui/src/config-ui/config-set.html
+++ b/appengine/config_service/ui/src/config-ui/config-set.html
@@ -274,8 +274,8 @@
         var error = parseInt(event.detail.error.message.match(/\d+/g));
         this.isLoading = false;
         if (error === 403) {
-          this.errorMessage = "Authorization required to view this config set. " +
-              "Please sign in.";
+          this.errorMessage = "Access denied. If you are not signed in, please do so. " +
+              "Otherwise, try again later.";

[Sergey Berezin, 2017/07/26 18:46:42]

"Access denied" is probably the only thing that we can say at this point. Trying
again later will likely not work, the user needs to gain access first.

Can we detect whether the user is signed in or not from Polymer? (maybe query
the auth element?)
Ideally, the message would change depending on whether the user is actually
logged in or not, e.g. "Access denied, please sign in." vs. "Access denied,
<username> is not authorized to access this config set. Request access or sign
in as a different user."

If detecting sign-in is nontrivial, I'd just leave it with "Access denied.".

         } else if (500 <= error && error < 600) {
           this.errorMessage = "Internal server error.";
         } else {