Update libphonenumber from 5.8.8 to 7.0.

I'm only interested in the recent change that makes libphonenumber's
COMPILE_ASSERT use static_assert, but this library hasn't been updated in
about one year so this brings in some 25 commits.

BUG=321833

Review URL: https://codereview.chromium.org/739643004

Cr-Commit-Position: refs/heads/master@{#306734}
3 files changed