Before CL 68017, the test verified that tokens expire exactly one day
after they are issued, within the time that Exchange() takes to execute.
A refactoring in the CL extended this time window to a whole day, making
the check much more lenient.
See: https://go-review.googlesource.com/c/oauth2/+/168017
Change-Id: I479db429f64b25a711624817c13f068b4675163e
Reviewed-on: https://go-review.googlesource.com/c/oauth2/+/630495
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Carlos Amedee <carlos@golang.org>