(PCP-428) fix restart_host test on windows agents
(PCP-428) fix restart_host test on windows agents

The previous commit works around some flaky host and pxp-agent restart
issues by using retry_on(), but did not take into account puppet command
pathing issues in windows.  this commit fixes this.
We also increase the max timeouts to 30 seconds. There have been a few
local failures for restart in under 10 seconds.

puppetlabs/pxp-agent,puppetlabs/pxp-agent,puppetlabs/pxp-agent