[BUG] whitelisted domains are NOT included into the exported backup json file

[ZG089]

⚠️ Before submitting:

• I have checked the existing issues to ensure this is not a duplicate. (Though it's mostly a followup with [BUG] Restore doesn't restore whole setting #222)
• I have updated BlockAds to the latest version available on GitHub.

Describe the bug
When I export my data from BlockAds, then later clear app data then import the exported file, my whitelisted domains aren't found at all / not even included into the json file.

To Reproduce
Steps to reproduce the behavior:

1. Open BlockAds and go to Firewall
2. Whitelist a domain
3. Go to Settings, Scroll down till you see 2 buttons for import and export
4. Clear app data
5. Open BlockAds again
6. Go to Settings, scroll down to import and export options
7. Click "Import" and pick the exported file
8. No whitelisted domain found

Expected behavior: to have my whitelisted domains backed up
Screenshots / Screen Records
If applicable, add screenshots or a short video to help explain your problem.

Environment details (CRITICAL for debugging):

• Device Model: Samsung Galaxy A11
• Android Version / Custom ROM: Android 12, OneUI 4.1 Core
• BlockAds Version: v6.5.2
• Source: GitHub Releases

BlockAds Configuration:

• Upstream DNS: Default
• Filters used: Default only (Standard Profile)
• Network: Wi-Fi