Feedback: Export to Google Sheets fails silently

### Impacted plugin

Jetpack

### Steps to Reproduce

1. Make sure your site have some form submissions
2. Connect Google Drive from Calypso's UI via Tools > Marketing > Connections
3. From `/wp-admin/edit.php?post_type=feedback` click "Export"
4. "Export" to Google Sheets

### A clear and concise description of what you expected to happen.

Modal should display an error about failed export. Ideally, suggesting the user a way to fix the issue.

### What actually happened

Nothing visually happened, but after exploring JS console, I noticed that `admin-ajax.php` (with `grunion_export_to_gdrive` payload) call returned a failure: `{"success":false,"data":{"errors":{"failed_to_fetch_data":["Unable to fetch the requested data."]},"error_data":{"failed_to_fetch_data":{"status":500}}}}`

Apparently, the above error was caused by a lack of required permissions for Drive connection. I haven't checked the second box when I was setting up the connection.

### Browser

Google Chrome/Chromium

### Other information

_No response_

### Platform (Simple, Atomic, or both?)

Atomic

### Reproducibility

Consistent

### Severity

None

### Available workarounds?

None

### Workaround details

_No response_

Start by tracing the `admin-ajax.php` request with the `grunion_export_to_gdrive` payload from the feedback export flow. Ensure the failed response is surfaced in the export modal with guidance for missing Google Drive permissions; reproduce the failure using the listed steps to verify the error is visible.

Written by the indexing model from the issue text.