Update required version of vms to ubuntu 22.04

Bug: b/274840966
Change-Id: I6ee191ee9c5e36b7373ce95a8a95feb109981acf
diff --git a/infra/config/global/main.star b/infra/config/global/main.star
index bbbf235..9fb3733 100755
--- a/infra/config/global/main.star
+++ b/infra/config/global/main.star
@@ -178,7 +178,7 @@
   if windows:
     dimensions["os"] = "Windows-10"
   else:
-    dimensions["os"] = "Ubuntu-18.04"
+    dimensions["os"] = "Ubuntu-22.04"
   if internal:
     dimensions["internal"] = "true"
   if normal: