Revert Windows VMs to Haswell CPU.
Revert Windows VMs to Haswell CPU.

This fixes the JVM hang during "Archive Artifacts" step that broke our
nightly builds.

Change-Id: Ia919abf11af105979a72325f5165a9b1dccf0899

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration