(isMobilePhone) update new number format for vi-VN locale

[hellovietduc]

• Update mobile phone number changing from 11 to 10 digits in vi-VN locale

Working demo: https://regexr.com/40or2

• Add tests for isMobilePhone vi-VN support

[chriso]

Thanks. Do you have a source for the changes?

[hellovietduc]

Thanks for your response.
Here's the official announcement from The Ministry of Information and Communications of The Socialist Republic of Vietnam: https://luatvietnam.vn/thong-tin/quyet-dinh-798-qd-btttt-2018-ke-hoach-chuyen-thue-bao-11-so-sang-10-so-163661-d1.html
Unfortunately, it's not English. But you can refer to the II.2.1 section of the announcement. You'll find 5 mobile network providers in Vietnam and the changes in prefixes of the phone number.
These changes started in September 15, 2018 (GMT+7). The old numbers can still be used until the end of November 14, 2018 (GMT+7) - stated in the II.2.4 section.
Here are some English articles that I found for more references:
https://vietnamnews.vn/economy/448837/11-digit-subscribers-to-be-switched-to-10-digits.html#xv9UyiYiow3sm1zk.97
https://english.vov.vn/society/hanoi-to-change-mobile-phone-operator-codes-from-september-15-377097.vov

[chriso]

Great! Thanks for the PR 😄