[roll] Roll fuchsia [dfv2][compat] Replace DevfsVnode with DeviceServer

Use the devfs_fidl::DeviceServer class to serve protocols from devfs.

Using this now means that devfs connections are stopped in the correct
place. The ddk-lifecycle test can be re-enabled in a followup CL.

The ClientRemote test needs to call PrepareStop now so that the devfs
connections are shut down correctly.

Multiply: compat_test
Original-Fixed: 117076
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/773312
Original-Revision: 7e97676170db175a1a64147a1550fbb556e6d914
GitOrigin-RevId: 35e6a6e7c35159d3d733ff15b8434ba6b15b4780
Change-Id: Ife20f1a3e0327e7d5ecd92deffc7fdeadd1aeb22
diff --git a/stem b/stem
index 30ea70d..5b3426c 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="b5e94efe1705ecbe4a4a09ae450c50d9ee15347e"/>
+             revision="7e97676170db175a1a64147a1550fbb556e6d914"/>
   </projects>
   <hooks>
     <hook name="install-environment"