[roll] Roll experiences [ermine] Fix PresentView() to allow null ViewController

Ermine's GraphicalPresenter.PresentView() implementation now copes
gracefully with callers which do not provide a ViewController
request for the View.

Original-Bug: 91199
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/experiences/+/628661
Original-Revision: 6e511372fc0ed86f5dcb04785fbd2619e3ca07f8
GitOrigin-RevId: e1a86fdc3c05585d6cba8a13859c24445239cf66
Change-Id: I0742f7304cbd6e94b1511143070cbda132e6da0c
diff --git a/flower b/flower
index bd137b3..f1fcc0b 100644
--- a/flower
+++ b/flower
@@ -11,6 +11,6 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/experiences"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="a081372f1f14be697919552fa4e431cf83c227d4"/>
+             revision="6e511372fc0ed86f5dcb04785fbd2619e3ca07f8"/>
   </projects>
 </manifest>