Temporary downgrade Azure-Cli to 2.5.1 (#959)

* hardcode 2.5.1 for win and linux

* change instllation to downgrade for ubuntu

images/linux/scripts/installers/azure-cli.sh

@@ -6,9 +6,16 @@
 
 # Source the helpers for use with the script
 source $HELPER_SCRIPTS/document.sh
+source $HELPER_SCRIPTS/os.sh
 
 # Install Azure CLI (instructions taken from https://docs.microsoft.com/en-us/cli/azure/install-azure-cli)
 curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash
+# Temporary downgrade to 2.5.1 installation until version 2.7.0 with the fix for the issue is not released https://github.com/actions/virtual-environments/issues/948
+# There is no 2.5.1 version for Ubuntu20
+if isUbuntu16 || isUbuntu18 ; then
+    label=$(getOSVersionLabel)
+    apt-get install -y --allow-downgrades azure-cli=2.5.1-1~$label
+fi
 
 # Run tests to determine that the software installed as expected
 echo "Testing to make sure that script performed as expected, and basic scenarios work"

images/win/scripts/Installers/Install-AzureCli.ps1

@@ -3,7 +3,8 @@
 ##  Desc:  Install Azure CLI
 ################################################################################
 
-Choco-Install -PackageName azure-cli
+# Temporary hardcode 2.5.1 installation until version 2.7.0 with the fix for the issue is not released https://github.com/actions/virtual-environments/issues/948
+Choco-Install -PackageName azure-cli -ArgumentList "--version=2.5.1"
 
 $AzureCliExtensionPath = Join-Path $Env:CommonProgramFiles 'AzureCliExtensionDirectory'
 New-Item -ItemType "directory" -Path $AzureCliExtensionPath