[roll] Roll fuchsia [magma] Add magma_sync(), Sync() to primary protocol

Clients today may use magma_get_error() to accomplish the
round-trip to MSD, but it's more of a side-effect there,
so this should be used instead, unless the client has
encountered a lost connection and wants the error status.

Original-Bug:12993

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/510678
Original-Revision: 7bcad1d7f642a9c423a24a7c502dff9abe91e7c2
GitOrigin-RevId: 39cde2b8ce546c9e825d570a651b92708b034748
Change-Id: I4165f09ff6da246568a149631e12a6557b4f9dec
diff --git a/stem b/stem
index 71f7606..37ddd3a 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="3cf58f1d19569eabd7f550b9e0a6f1f241fd5a49"/>
+             revision="7bcad1d7f642a9c423a24a7c502dff9abe91e7c2"/>
   </projects>
   <hooks>
     <hook name="install-environment"