Regional adblock filters are not pre-selected after changing locale

[btlechowski]

Follow up to #4367

Steps to Reproduce

1. Clean profile
2. Run Brave on Linux using LANG=pl_PL.UTF-8 LANGUAGE=pl_PL /usr/bin/brave-browser-beta --lang=pl_PL
3. Open brave://adblock and check if all pl filter lists are selected
4. Close Brave
5. Run Brave on Linux using LANG=fr_FR.UTF-8 LANGUAGE=fr_FR /usr/bin/brave-browser-beta --lang=fr_FR
6. Open brave://adblock and check if fr filter list is selected

Note: Running Brave in FR locale on clean profile will pre-select proper filter list

Actual result:

PL filters are selected

Expected result:

FR filter is selected

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	1.50.93 Chromium: 111.0.5563.64 (Official Build) beta (64-bit)
Revision	c710e93d5b63b7095afe8c2c17df34408078439d-refs/branch-heads/5563@{#995}
OS	Ubuntu 18.04 LTS

cc @rebron @antonok-edm