IIS: Application Pool parameters always result in a changed catalog

Basic Info
*Module Version: IIS 4.0.0
*Puppet Version: 2017.2.1
*OS Name/Version: Windows 2012 R2

Description
Some parameters in the iis_application_pool type are set on every run and cause a refresh of the application pool.

Desired Behavior:
The parameters should be idempotent and not cause a refresh of the application pool

Actual Behavior:
Parameters like restart_memory_limit and user_name cause the agent runs to refresh the service. A specific use case is the restart_memory_limit.

When adding the parameter to the minimal example in the readme we see the issue on a vanilla Windows 2012r2 server.

  iis_application_pool { 'minimal_site_app_pool':

    ensure                  => 'present',

    managed_pipeline_mode   => 'Integrated',

    managed_runtime_version => 'v4.0',

    state                   => 'Started',

    restart_memory_limit    => '3500000',

  }

  ->   iis_site { 'minimal':

    ensure          => 'started',

    physicalpath    => 'c:\\inetpub\\minimal',

    applicationpool => 'minimal_site_app_pool',

  }

PS C:\Users\Administrator> puppet agent -t

Notice: /Stage[main]/Profile::Iis/Iis_application_pool[minimal_site_app_pool]/restart_memory_limit: restart_memory_limit changed '' to '3500000'

Notice: /Stage[main]/Profile::Iis/Iis_site[minimal]/ensure: ensure changed 'stopped' to 'started'

PS C:\Users\Administrator> puppet agent -t

Notice: /Stage[main]/Profile::Iis/Iis_application_pool[minimal_site_app_pool]/restart_memory_limit: restart_memory_limit changed '' to '3500000'

The agent debug log from one of these runs is attached as restart_memory_limit.txt. It looks like the issue is the return from Get-WebConfiguration -Filter '/system.applicationHost/applicationPools/add' shows the "restart_memory_limit": "",. When looking at IIS, we can see the recycling.periodicRestart.memory set properly.