[Ubuntu] Tight composer version to 2.2.9 for Ubuntu Server 18 (#5321)

* [Ubuntu] Tight composer verstion to 2.2.9 for Ubuntu Server 18

* Remove extra line

* remove double quotes

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

@@ -20,6 +20,10 @@ Describe "PHP" {
         "composer --version" | Should -ReturnZeroExitCode
     }
 
+    It "Composer 2.2.9 on Ubuntu Server 18" -Skip:(-not (Test-IsUbuntu18)) {
+        composer --version | Should -Match "2.2.9"
+    }
+
     It "Pear" {
         "pear" | Should -ReturnZeroExitCode
     }