[roll] Roll fuchsia [artifactory] Ignore missing transfer manifests

Some buildbots only build a subset of targets and might not produce a
product bundle. This changes artifactory to treat a missing transfer
manifest as if there are no artifacts from a product bundle to upload.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/900441
Original-Revision: a287db0ee4516246d5890fd62e85379307166e0a
GitOrigin-RevId: 6da4440cb33fc731e674c5f6692b2b51ba1b9781
Change-Id: I592af948e5671ee6ee40f73e3fb204ffe07a2fae
diff --git a/stem b/stem
index ff5ee99..ec1b410 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="f59888871cc38143183bf31036b8349696ced7bc"/>
+             revision="a287db0ee4516246d5890fd62e85379307166e0a"/>
   </projects>
   <hooks>
     <hook name="install-environment"