net/http: run TestRequestWriteTransport with fake time to avoid flakes
This test verifies whether or not we use the chunked encoding when
sending a request with a body like io.NopCloser(strings.NewReader("")).
This depends on whether the transport can read a single byte from the
request body within 200ms, which is flaky on very slow builders.
Use fake time to avoid flakes.
Fixes #52575
Change-Id: Ie11a58ac6bc18d43af1423827887e804242dee30
Reviewed-on: https://go-review.googlesource.com/c/go/+/710737
Auto-Submit: Nicholas Husin <nsh@golang.org> Reviewed-by: Nicholas Husin <husin@google.com> Reviewed-by: Nicholas Husin <nsh@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>