[roll] Roll fuchsia [submodules] Update submodule pins

This change synchronizes submodule revisions with Jiri manifest state.
These revisions have no bearing on Fuchsia builds or local checkouts
and are only used by Code Search.

If you wish to update a repository's revision, update the corresponding
Jiri manifest and the change will automatically be synchronized to
submodules.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1277456
Original-Revision: b4b5a0741195a327d250f1f04786217b6add6d56
GitOrigin-RevId: b52c8c98e97fb0f37f31dffcaba9be807075fca9
Change-Id: I58f9c476cebaa541f5cba93eaa985f059cc15332
diff --git a/stem b/stem
index 8a2a885..d7967e9 100644
--- a/stem
+++ b/stem
@@ -8,7 +8,7 @@
              root=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="5cc01a134719a9add89c3e4e98aaca015879aeb2"
+             revision="b4b5a0741195a327d250f1f04786217b6add6d56"
              />
   </imports>
   <projects>