Update Test-AzLandingZone for az cli API change

[barrjam]

Test-AzLandingZone

The file: AzLandingZone/Public/Test-AzLandingZone.ps1 uses the

 az ad signed-in-user show --query objectId -o tsv
<returns nothing

az ad signed-in-user show --query id -o tsv        
2f40dad4-39fb-4b66-9293-173f034cec3f

So objectId has changed to id

Latest version of az cli is 2.42.0

PS /AzLandingZone/AzLandingZone> az upgrade
This command is in preview and under development. Reference and support levels: https://aka.ms/CLI_refstatus
You already have the latest azure-cli version: 2.42.0

AzLandingZone/AzLandingZone> az version
{
  "azure-cli": "2.42.0",
  "azure-cli-core": "2.42.0",
  "azure-cli-telemetry": "1.0.8",
  "extensions": {
    "account": "0.2.5",
    "alertsmanagement": "0.2.2",
    "log-analytics": "0.2.2",
    "resource-graph": "2.1.0",
    "scheduled-query": "0.5.1",
    "sentinel": "0.2.0",
    "subscription": "0.1.5"
  }
}

[barrjam]

Already Fixed