SqlAG: Requires Optional Parameters

Details of the scenario you tried and the problem that is occurring:
If the optional parameters ConnectionModeInPrimaryRole and FailureConditionLevel are not provided in the configuration for an Availability Group, Test-TargetResource reports a failure.

The DSC configuration that is using the resource (as detailed as possible):

Configuration SampleConfig 
{
    Import-DscResource -ModuleName xSQLServer -Name xSQLServerAlwaysOnAvailabilityGroup

    Node localhost 
    {
        xSQLServerAlwaysOnAvailabilityGroup 'TestAG'
        {
            Name = 'TestAG'
            SQLServer = 'localhost'
            SQLInstanceName = 'MSSQLSERVER'
            Ensure = 'Present'
            FailoverMode = 'Manual'
        }
    }
}

Version of the Operating System, SQL Server and PowerShell the DSC Target Node is running:
Operating System: Windows Server 2012 R2
PowerShell Version: 5.0

What module (SqlServer or SQLPS) and which version of the module the DSC Target Node is running:
SQLPS (130)

Version of the DSC module you're using, or 'dev' if you're using current dev branch:
8.2.0.0

Start with the xSQLServerAlwaysOnAvailabilityGroup resource and its Test-TargetResource behavior. Reproduce the sample configuration without ConnectionModeInPrimaryRole or FailureConditionLevel, then verify that omitted optional parameters no longer cause a reported failure.