[roll] Roll fuchsia [net-test-realm] Log multicast ops

We're observing a flaky hang in network-conformance testing that seems
to be caused by the net-test-realm plugin's join/leave-multicast-group
commands. Since this is proving difficult to reproduce at desk, let's
add debug prints to see if we can gather more information from CI.

Original-Bug: 136188
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/952592
Original-Revision: 14568d0c944886dc72cd3a8deccacbd9cbd744ad
GitOrigin-RevId: 81eaa14b3acc95cfc3a1f10fa5d8666325f41e2e
Change-Id: I686dc277d82f64d442b78848d16d3b05f9db2ec7
diff --git a/stem b/stem
index f5d6750..b00f29c 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="48a0782f35d5341e740531173d1b533be6430a58"/>
+             revision="14568d0c944886dc72cd3a8deccacbd9cbd744ad"/>
   </projects>
   <hooks>
     <hook name="install-environment"