[roll] Roll fuchsia [bazel][assembly] Fix the board configuration rule

The root cause with former failures was, although we indeed copied the
files marked in "LABEL(*)" into the sandbox, those are not relative to
the location of board configuration file. We copy the file into the
expected directory now.

I tested with RTC driver and it works correctly.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/953453
Original-Revision: 4c1bde42796cf14bdc6556267051c9e465e7b1c2
GitOrigin-RevId: 31a61f0021af10b5e9ffe74726a2af3d61d625a0
Change-Id: Icb1964396726fee55563ecf58ea9643350c556e0
diff --git a/stem b/stem
index 51c134b..e4434ba 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="120a4b64baab28e12a3b672fa94c3db7f4390d92"/>
+             revision="4c1bde42796cf14bdc6556267051c9e465e7b1c2"/>
   </projects>
   <hooks>
     <hook name="install-environment"