[usb-virtual-bus] Disable test due to flakes

Change-Id: Ib3d92b30c8739922c661eb030421366333977ba0
diff --git a/zircon/system/utest/BUILD.gn b/zircon/system/utest/BUILD.gn
index ca2b9b3..7ec4c46 100644
--- a/zircon/system/utest/BUILD.gn
+++ b/zircon/system/utest/BUILD.gn
@@ -202,7 +202,6 @@
       "timers",
       "trace",
       "usb",
-      "usb-virtual-bus",
       "util",
       "vdso",
       "vdso-base",
@@ -214,6 +213,7 @@
 
       # disabled for now:
       #"bad-kernel-access",
+      #"usb-virtual-bus",
 
       # TODO(fuzztest): "edid"
     ]