[roll] Roll fuchsia [starnix][functionfs] Change block to be interruptible

FunctionFS operations were previous blocked on uninterruptible recv()s
from mpsc channel. After this change, they should be interruptible and
are in RunState::Event.

Original-Original-Bug: 507976854

Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1637695
Original-Original-Revision: 4a86244de6f6777e9d906302a0ff7ba060150738
GitOrigin-RevId: a7196fe4b8f094be234f8151cf817e2a96fadf07
Change-Id: I48db6bbe24f11e0ff45d071e505c39ac40dc5214
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1644814
Cr-Commit-Position: refs/heads/main@{#194393}

stem

diff --git a/stem b/stem
index 4897619..c31e383 100644
--- a/stem
+++ b/stem
@@ -8,6 +8,6 @@
             manifest="manifests/platform"
             root=""
             remote="https://fuchsia.googlesource.com/fuchsia"
-            revision="b7a8d3d0a4bdd430fe12cde5a1bb18ec576ef4c4"/>
+            revision="4a86244de6f6777e9d906302a0ff7ba060150738"/>
   </imports>
 </manifest>