Wait for upto 5s for IDP sign in to finish, after popup is closed.

In some cases (Fiefox or mobile or if opener is an iframe), the popup is closed by the oauth helper code
right after sign in has completed at the IDP. The IDP response still needs to be processed by the SDK + signInWithIdp API
call needs to be invoked. This can take upto 7s, if there is a blocking function configured. Increase the poller timeout
to 8s, so it does not reject the sign in with popup-closed-by-user error.

Author: prameshj

packages/auth/src/platform_browser/strategies/popup.ts

@@ -46,10 +46,13 @@ import { FederatedAuthProvider } from '../../core/providers/federated';
 import { getModularInstance } from '@firebase/util';
 
 /*
- * The event timeout is the same on mobile and desktop, no need for Delay.
+ * The event timeout is the same on mobile and desktop, no need for Delay. Set this to 8s since
+ * blocking functions can take upto 7s to complete sign in, as documented in:
+ * https://cloud.google.com/identity-platform/docs/blocking-functions#understanding_blocking_functions
+ * https://firebase.google.com/docs/auth/extend-with-blocking-functions#understanding_blocking_functions
  */
 export const enum _Timeout {
-  AUTH_EVENT = 2000
+  AUTH_EVENT = 8000
 }
 export const _POLL_WINDOW_CLOSE_TIMEOUT = new Delay(2000, 10000);
 
@@ -282,7 +285,9 @@ class PopupOperation extends AbstractPopupRedirectOperation {
       if (this.authWindow?.window?.closed) {
         // Make sure that there is sufficient time for whatever action to
         // complete. The window could have closed but the sign in network
-        // call could still be in flight.
+        // call could still be in flight. This is specifically true for
+        // Firefox or if the opener is in an iframe, in which case the oauth
+        // helper closes the popup.
         this.pollId = window.setTimeout(() => {
           this.pollId = null;
           this.reject(