SPDistributedCacheService: Add support for backgroundGC

Resource proposal

The Article Installing Windows Server AppFabric updates SharePoint 2013 Servers recommends enabling the backgroundGC for the DistributedCacheService.exe via the DistributedCacheService.exe.config file.

Details Cumulative update package 3 for Microsoft AppFabric 1.1 for Windows Server.

SharePoint Subscription Edition enables this by default. All previous versions need to enable it manually.
Since the SPDistributedCacheService has to run on every Node it would be a good fit, to add this to the ressource.

I can create a pull request, if this is the right ressource

Proposed properties

Special considerations or limitations

Code Example

[system.reflection.assembly]::LoadWithPartialName("System.Configuration") | Out-Null

# intentionally leave off the trailing ".config" as OpenExeConfiguration will auto-append that
$configFilePath = "$env:ProgramFiles\AppFabric 1.1 for Windows Server\DistributedCacheService.exe"
$appFabricConfig = [System.Configuration.ConfigurationManager]::OpenExeConfiguration($configFilePath)

# if backgroundGC setting does not exist add it, else check if value is "false" and change to "true"
if($appFabricConfig.AppSettings.Settings.AllKeys -notcontains "backgroundGC")
{
    $appFabricConfig.AppSettings.Settings.Add("backgroundGC", "true")
}
elseif ($appFabricConfig.AppSettings.Settings["backgroundGC"].Value -eq "false")
{
    $appFabricConfig.AppSettings.Settings["backgroundGC"].Value = "true"
}

# save changes to config file
$appFabricConfig.Save()