Stream Firestore to BigQuery extension installation fails

### [REQUIRED] Step 2: Describe your configuration

- Extension name: firebase/firestore-bigquery-export@0.2.5
- Extension version: 0.2.5
- Configuration values (redact info where appropriate):
- basically the defaults, setting the firestore location to my location

### [REQUIRED] Step 3: Describe the problem
When I try to install the extension, for example

https://console.firebase.google.com/project/PROJECT-460819/extensions/install?ref=firebase%2Ffirestore-bigquery-export@0.2.5

it eventually fails:


Details look like:

`; RESOURCE_ERROR at /deployments/firebase-ext-firestore-bigquery-export/resources/initBigQuerySync: {"ResourceType":"gcp-types/cloudfunctions-v1:projects.locations.functions","ResourceErrorCode":"400","ResourceErrorMessage":{"code":400,"message":"Failed to create 1st Gen function projects/PROJECT-460819/locations/us-central1/functions/ext-firestore-bigquery-export-initBigQuerySync: Default service account '998640598660-compute@developer.gserviceaccount.com' doesn't exist. Please recreate this account or specify a different account. Please visit https://cloud.google.com/functions/docs/troubleshooting for in-depth troubleshooting documentation.","status":"FAILED_PRECONDITION","statusMessage":"Bad Request","requestPath":"https://cloudfunctions.googleapis.com/v1/projects/PROJECT-460819/locations/us-central1/functions","httpMethod":"POST"}}; RESOURCE_ERROR at /deployments/firebase-ext-firestore-bigquery-export/resources/syncBigQuery: {"ResourceType":"gcp-types/cloudfunctions-v1:projects.locations.functions","ResourceErrorCode":"400","ResourceErrorMessage":{"code":400,"message":"Failed to create 1st Gen function projects/PROJECT-460819/locations/us-central1/functions/ext-firestore-bigquery-export-syncBigQuery: Default service account '998640598660-compute@developer.gserviceaccount.com' doesn't exist. Please recreate this account or specify a different account. Please visit https://cloud.google.com/functions/docs/troubleshooting for in-depth troubleshooting documentation.","status":"FAILED_PRECONDITION","statusMessage":"Bad Request","requestPath":"https://cloudfunctions.googleapis.com/v1/projects/PROJECT-460819/locations/us-central1/functions","httpMethod":"POST"}}; RESOURCE_ERROR at /deployments/firebase-ext-firestore-bigquery-export/resources/fsexportbigquery: {"ResourceType":"gcp-types/cloudfunctions-v2beta:projects.locations.functions","ResourceErrorCode":"404","ResourceErrorMessage":{"code":404,"message":"Service account projects/-/serviceAccounts/998640598660-compute@developer.gserviceaccount.com was not found.","status":"NOT_FOUND","statusMessage":"Not Found","requestPath":"https://cloudfunctions.googleapis.com/v2beta/projects/PROJECT-460819/locations/us-central1/functions","httpMethod":"POST"}}; RESOURCE_ERROR at /deployments/firebase-ext-firestore-bigquery-export/resources/setupBigQuerySync: {"ResourceType":"gcp-types/cloudfunctions-v1:projects.locations.functions","ResourceErrorCode":"400","ResourceErrorMessage":{"code":400,"message":"Failed to create 1st Gen function projects/PROJECT-460819/locations/us-central1/functions/ext-firestore-bigquery-export-setupBigQuerySync: Default service account '998640598660-compute@developer.gserviceaccount.com' doesn't exist. Please recreate this account or specify a different account. Please visit https://cloud.google.com/functions/docs/troubleshooting for in-depth troubleshooting documentation.","status":"FAILED_PRECONDITION","statusMessage":"Bad Request","requestPath":"https://cloudfunctions.googleapis.com/v1/projects/PROJECT-460819/locations/us-central1/functions","httpMethod":"POST"}}`

#### Steps to reproduce:

Something suspicious: when I click the "Grant" buttons on this page of the installation sequence,


I don't get positive feedback... the buttons just disappear:


##### Expected result

Extension installs cleanly

##### Actual result

Extension fails to install!

I have also tried to install the extension with the command line, which generates a slightly different error:

```
=== Deploying to 'PROJECT-460819'...

i deploying extensions
i extensions: ensuring required API firebaseextensions.googleapis.com is enabled...
✔ extensions: required API firebaseextensions.googleapis.com is enabled
i extensions: ensuring required API compute.googleapis.com is enabled...
✔ extensions: required API compute.googleapis.com is enabled

Error: Request to https://cloudresourcemanager.googleapis.com/v1/projects/PROJECT-460819:setIamPolicy had HTTP Error: 400, Service account 998640598660-compute@developer.gserviceaccount.com does not exist.
```

I strongly suspect this is related to the following issues, but since it involved the Firebase web interface, I thought it deserved its own bug:
- https://github.com/firebase/extensions/issues/2383
- https://github.com/firebase/firebase-tools/pull/8566