[infra] Upgrade Win to 2019

Change-Id: I709792f697d5acc5e1c7c0df361f48d8170e2a34
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/261377
Commit-Queue: Ben Wagner aka dogben <benjaminwagner@google.com>
Reviewed-by: Ravi Mistry <rmistry@google.com>
3 files changed