Merged PR 473444: Update Roslyn server

Contains https://dnceng.visualstudio.com/internal/_git/dotnet-roslyn/commit/0490d22a921b228e6d530789036a31077b2f7870?tab=details

Author: arunchndr

package.json

@@ -35,7 +35,7 @@
     }
   },
   "defaults": {
-    "roslyn": "4.7.0-2.23272.2",
+    "roslyn": "4.7.0-2.23272.4",
     "omniSharp": "1.39.6",
     "razor": "7.0.0-preview.23269.1"
   },