Use year instead of week year in date formatter
Use year instead of week year in date formatter

YYYY is used for week year, as opposed to yyyy for the actual year.
This can lead to un expected behavior.

For example "2014-12-31" would return 2015 for YYYY because the
first week of 2015 starts on the 29th.

PiperOrigin-RevId: 227518228
Change-Id: Ia8ccd22ec119d69ae174f232d8e8a40cfaf914de

google/copybara,google/copybara,google/copybara