Webcompat Exception Manager should revert to remote list when user selection matches it

[ShivanKaul]

Description

User selection for a particular fingerprinting protection overrides the one set by the remote list. Once the user overrides the default being set by the remote list, we persist that, so even if the setting changes in the latest copy of the remote list, it does not get applied. So even if the user toggles the default from X to Y, and then back to X, remote list updates will stop applying.

We should modify this behaviour so that as long as the user's selection matches the current remote list, new list updates will apply.

Steps to reproduce

1. Manually override the default fingerprinting protection set by https://github.com/brave/adblock-lists/blob/master/brave-lists/webcompat-exceptions.json
2. Set it back to default
3. Change the remote list default (can be done on the local list)

Actual result

Updated rule will not apply

Expected result

Updated rule should apply given that the user's selection is the default.

Reproduces how often

Easily reproduced

Brave version (brave://version info)

1.69.x onwards (which is when the WEM PR was merged in)

Channel information

• [ ] release (stable)
• [X] beta
• [X] nightly

Reproducibility

• [ ] with Brave Shields disabled
• [ ] with Brave Rewards disabled
• [ ] in the latest version of Chrome

Miscellaneous information

No response

[arthuredelstein]

We are going to additionally check whenever the remote list is updated and delete the user setting if it matches the remote setting.