Sheriff: Disable session.RetrieveActiveSessions

TBR=mnissler@chromium.org
TBR=hidehiko@chromium.org

Bug: 1117324
Change-Id: Iec44ae22a5c0452f9b6489c9e0c567e957c68b8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359877Reviewed-by: Fergus Dall <sidereal@google.com>
Commit-Queue: Fergus Dall <sidereal@google.com>
Cr-Commit-Position: refs/heads/master@{#798951}

chromeos/BUILD.gn

@@ -322,6 +322,9 @@ if (is_chromeos_device) {
 
       # crbug.com/1114752
       "arc.ContainerMount",
+
+      # crbug.com/1117324
+      "session.RetrieveActiveSessions",
     ]
   }