Issue title: Install IIS service on Visual Studio 2019 image
 Issue body: Original issue: https://help.appveyor.com/discussions/problems/24344-vs-2019-build-cant-find-iis-service
 Comments: 
 Comment 0: Cheers for raising and for the workaround. Any rough ideas when this'll reach prod?
 Comment 1: @wozzo 1-2 weeks, but cannot give a specific promises
 Comment 2: Any movement on this?
 Comment 3: @FeodorFitsner @IlyaFinkelshteyn is this any closer to being done?
 Comment 4: We plan to update `Visual Studio 2019`  image this week.
 Comment 5: @IlyaFinkelshteyn I saw the milestone was dated yesterday, has this gone out yet?
 Comment 6: We will switch image today tonight, sorry for those delays.
 Comment 7: Thanks.
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