[MSYS-808] Fix system users issue for windows_task

[NAshwini]

Fix the issue of no mapping while creating Windows task for SYSTEM USERS.
As per issue chef/chef#7227

Signed-off-by: NAshwini ashwini.nehate@msystechnologies.com

[btm]

So, is this the user we're using to create the task, or the user that the task will run as?

Before this change, who would the task run as if a user wasn't passed to the resource but we weren't running as system/localsystem? Would the task run as the current user? We weren't passing a username, but something was still looking up the user as we were getting an error when the system/localsystem user didn't exist. Presumably the WIN32OLE call was doing that look up.

I'm worried that there's a behavior change here beyond just fixing the regression when running as system.

Are we sure that the created task is still running as the same user when we're not passing user/password but we're not running as system?

Is the created task still running in the same way when we do pass a username and password? We were passing nil here before.

[Vasu1105]

@btm since user set in new_work_item is nil we were getting that user so we are settling it as SYSTEM when user is not available. We have method call for set_account_information and configure_principals after new_work_item which updates task definition and sets the user based on what is set in recipe so if user is not provided default will be system. And if username and password is used that will be set. And it set author of task and run task as SYSTEM if not provided or whatever provided in recipe.

https://github.com/chef/chef/blob/master/lib/chef/provider/windows_task.rb#L141:L142
https://github.com/chef/chef/blob/master/lib/chef/provider/windows_task.rb#L540:L551

https://github.com/chef/win32-taskscheduler/blob/ole/lib/win32/taskscheduler.rb#L303
https://github.com/chef/win32-taskscheduler/blob/ole/lib/win32/taskscheduler.rb#L1226