Support new Git output in GitRepository
Support new Git output in GitRepository

A recent change in Git has updated the error
message when a sha1 is fetched and not found.

BUG=80489039
PiperOrigin-RevId: 198621008
Change-Id: If36353e8c696d48522384d3a342bcc34658c086b

google/copybara,google/copybara,google/copybara