[roll] Roll fuchsia [sdk][flutter] Add FocusState.requestFocus.

Soft transition FuchsiaViewsService.requestFocus to
FocusState.requestFocus.

Original-Bug: 79740
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/550061
Original-Revision: ad39403e62911e4a422d83f7406407e1b160f40f
GitOrigin-RevId: 3b47adc1edeafb79f6ef4fab7c681e1204fcce78
Change-Id: Ic000cc2dc602cc043769eb1bca40bd41223f9f38

stem

diff --git a/stem b/stem
index 521affc..c408da6 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="bc79c44c0c45ab6a49c7f0b47040505049892ced"/>
+             revision="ad39403e62911e4a422d83f7406407e1b160f40f"/>
   </projects>
   <hooks>
     <hook name="install-environment"