[roll] Roll fuchsia Reland "[ffx][mdns_discovery]: add MdnsWatcher struct"

This is a reland of commit 8f99f58f4c85cd93cb1d6562aeb2db31c11a8cec

Original change's description:
> [ffx][mdns_discovery]: add MdnsWatcher struct
>
> Simple struct that emits ffx::MdnsEventType events that can be passed to
> a handler closure (trait is MdnsEventHandler which is implemented for
> FnMut).
>
> To be used in generic `discovery` library.
>
> Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/947117

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/951994
Original-Revision: f029ad0ffee12bbba778582ba5e983b279cd48e8
GitOrigin-RevId: 105a293133fe2a380aa46e5ea17a9d87bca11d0f
Change-Id: I9e9dcc1c2a89b56781c9a4688224cfaf7ed56b89
diff --git a/stem b/stem
index 6d81c06..313bcab 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="e4fda3b2c812633e76c6e11b6e12d677c952f6cd"/>
+             revision="f029ad0ffee12bbba778582ba5e983b279cd48e8"/>
   </projects>
   <hooks>
     <hook name="install-environment"