[Ubuntu] Remove Ubuntu16 related code from the VE repository (#4336)

images/linux/scripts/tests/Apt.Tests.ps1

@@ -49,6 +49,11 @@ Describe "Apt" {
             $toolName = "netstat"
         }
 
+        if ($toolName -eq "mercurial")
+        {
+            $toolName = "hg"
+        }
+
         (Get-Command -Name $toolName).CommandType | Should -BeExactly "Application"
     }
 }