In a non-scripted pipeline, a vSphere Build Step set to vSphere Action 'Power-Off VM', the 'Shutdown gracefully' option is always shown unchecked when opening a job Configuration.

When the option is enabled and the configuration saved, the Job Config History shows:
<shutdownGracefully>true</shutdownGracefully>

If the Configuration is reopened and resaved without re-enabling this option, the Job Config History shows:
<shutdownGracefully>false</shutdownGracefully>

 Note:  version 2.18 works correctly.

Reproduction:

1. Create a job with vSphere Build Step set to vSphere Action 'Power-Off VM', the 'Shutdown gracefully' option enabled, and save the configuration
2. Reopen Configuration for this job>  'Shutdown gracefully' option is incorrectly shown as disabled
3. Save Configuration without modifying this option> The shutdownGracefully option has been set to false in job configuration