[roll] Roll fuchsia [async-utils] Add FutureMap asynchronous data structure.

FutureMap behaves like a HashMap that implements `Stream` when the value
is a type implementing `Future`.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/452064
Original-Revision: 7e0a8827101891bbe5dad7426d44f029216b93b9
GitOrigin-RevId: 1ea40e160c4ab08b0dc0badbc78d32b264383899
Change-Id: Ic2ad9386fed1c2a49be8f3dd8d0f61d2ebf61d59
diff --git a/stem b/stem
index 4e28c81..c21cb75 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="2ddf691e2f49ec5cd0a6f9509d2a7199914f62b3"/>
+             revision="7e0a8827101891bbe5dad7426d44f029216b93b9"/>
   </projects>
   <hooks>
     <hook name="install-environment"