This is a follow up for bug 1630764.

Currently, Yandex search shortcut variants share the same url "yandex.com", which points to the same tippytop icon for yandex.com. Per client's request, we should use the Russian edition for yandex.ru.

https://hg.mozilla.org/mozilla-central/rev/e5dc3106541e

STR for QA:

• Change the pref "browser.search.region" to "RU"
• Flip the pref "intl.multilingual.enabled", and install the "ru" languange pack from l10n-central
• Before switching the browser locale to "ru", click on the "Add search engine" from the Topsites context menu. And you should see the Yandex search shortcut for "yandex.com" with the "Y" logo
• Then switch to the "ru" locale, and restart the browser
• On the "Add search engine" form, you should see the Yandex logo in Russian
• Once you add it and click on it, it should take you to quantumbar and search with "yandex.ru"
• Switch back to "en-US", the pinned Yandex shortcut should also switch back to the logo with "Y"

I have verified that the "Yandex.ru" search shortcut is correctly displayed by using Firefox Nightly 79.0a1 (Build ID: 20200624093107) en-US with the following changes:

• The value of the "browser.search.region" pref set to "RU".
• The "ru" language pack installed.
• The "Language" in the "about:preferences" is set to "Russian".
  I have also verified that switching back to the "English (United States)" language in the "about:preferences" page will correctly display the
  "Yandex.com" search shortcut.