env/windows: more network selection fixes

Another addition of "--network=vpc" later in build.bash
in the image capture phase.

Updates golang/go#35006.

Change-Id: I5e23a693a6042f19a309d3fe7ddedba30e95cc1f
Reviewed-on: https://go-review.googlesource.com/c/build/+/406858
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Alex Rakoczy <alex@golang.org>
diff --git a/env/windows/build.bash b/env/windows/build.bash
index 4085180..a7931f7 100755
--- a/env/windows/build.bash
+++ b/env/windows/build.bash
@@ -107,6 +107,7 @@
 
 echo "Creating new machine with image"
 gcloud compute instances create --machine-type="$MACHINE_TYPE" --image "$BUILDLET_IMAGE" "$TEST_INSTANCE_NAME" \
+       --network=default-vpc \
        --project="$PROJECT_ID" --metadata="buildlet-binary-url=https://storage.googleapis.com/go-builder-data/buildlet.windows-amd64" \
        --zone="$ZONE"