[roll] Roll fuchsia [gvisor_syscall_tests] Disable debug logs for loopback tests

These tests sometimes time out seemingly due to excessive logspam, so
add a way to hide lower-than-INFO logs from netstack3 and use it for
just the loopback suite.

Multiply: netstack3_loopback_syscall
Original-Fixed: 417621958
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1276865
Original-Revision: d6dc24ace37227b1f9779857ffd7487aaa53c5fb
GitOrigin-RevId: 64361583e09ed2c029b7443588e3e43ea67a9f65
Change-Id: I5a4b4ad5d222d7a8c8304035708502ceb60274f8
diff --git a/stem b/stem
index 1c14658..117b2a1 100644
--- a/stem
+++ b/stem
@@ -8,7 +8,7 @@
              root=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="47f753a2ed570f0bcc988d69f6bc92414f8440ed"
+             revision="d6dc24ace37227b1f9779857ffd7487aaa53c5fb"
              />
   </imports>
   <projects>