[roll] Roll fuchsia [netstack3] Deliver UDP packets with 0 src port

Deliver UDP packets with a source port number of 0 to UDP listeners.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/860706
Original-Revision: a56f9c807bad503abc0ebf2197b6d7c9c6767f9c
GitOrigin-RevId: 866d852357fe5953715844432e5986dace639032
Change-Id: I5701ebfbc84efdfa7337fe75ecf116873835da94
diff --git a/stem b/stem
index 210e06d..74d7241 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="e8a8bee9a718e5d6ea5c36fff49e689ef73e2d26"/>
+             revision="a56f9c807bad503abc0ebf2197b6d7c9c6767f9c"/>
   </projects>
   <hooks>
     <hook name="install-environment"