Revert "Bug 42397: Change RFP-spoofed TZ to Atlantic/Reykjavik."

This reverts commit 6d9095b1.

ma1 authored May 31, 2024 and Pier Angelo Vendrame committed Jun 03, 2024

Atlantic/Reykjavik stays on UTC during all the year, but it is less
likely to be blocked than plan UTC.

Differential Revision: https://phabricator.services.mozilla.com/D212131

Revert "Bug 41966: Allow removing locales from the locale alternatives list."

This reverts commit bba294a4.

henry authored May 29, 2024 and Pier Angelo Vendrame committed Jun 03, 2024

Bug 1851618 - Allow removing packaged locales from requestedLocales. r=settings-reviewers,eemeli,Gijs

We open up the UI to allow the user to remove locales from their
requestedLocales list, except for the default locale.

Differential Revision: https://phabricator.services.mozilla.com/D209930