🐛 [firestore-bigquery-export] There was an unknown error while processing the request.

### [REQUIRED] Step 2: Describe your configuration
I am trying to install the extension from here: https://extensions.dev/extensions/firebase/firestore-bigquery-export

### [REQUIRED] Step 3: Describe the problem

#### Steps to reproduce:

Install the extension from here: https://extensions.dev/extensions/firebase/firestore-bigquery-export
I get in the end after clicking "Install Extension" the following error: "There was an unknown error while processing the request.". I see in the HTTP calls 2 400 responses for "INVALID_ARGUMENT", but this information needs to be surfaced in the beginning, we can't expect a user checking the http calls for errors...

One of the 400 is when I try to grant Pub/Sub Service Agent - roles/iam.serviceAccountTokenCreator, the HTTP response I get is "Service account XYZ does not exist.".

The other one is "Project id XYZ is invalid; must be between 6 and 30 characters". First of all, the UI should block me, secondly even with a shorter ID seems to fail anyway.