Only use en-US locale in date conversion.

en-GB breaks some date conversions.

Keeping locale in timezone info, because we should at some point be able to move TimeUtils.format into Timestamp class, and format based on the ABT locale as well.
Currently we always format in en-US.

Bug: b/272430478
Test: npm run test:unit:ci
Change-Id: I0a314ed6ceb05ea5d08659444b718e3b95edbc7e
3 files changed