[roll] Roll fuchsia [starnix] Establish connection between Starnix and MouseSource

This CL establishes the connection between Starnix and the MouseSource
in InputPipeline. We also create a basic skeleton in Starnix for a Mouse
relay that, for now, just watches for incoming MouseEvents from Input Pipeline.

Original-Bug: b/380119987
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1200308
Original-Revision: f6cde6ae20b40837978c51f6771d2ea1222aee0f
GitOrigin-RevId: 28375e4a4f0c7c82ea12a677bf0ada04be82aa3e
Change-Id: Ie03120a6fb3a9206e5fafad8411d96a062597fd7
diff --git a/stem b/stem
index a5b50fb..91618b4 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="675859e6ce8e4f11d42252ba9ebb0d7c15efb047"/>
+             revision="f6cde6ae20b40837978c51f6771d2ea1222aee0f"/>
   </projects>
   <hooks>
     <hook name="install-environment"