omni_emulator: follow servicetracker property rename

Change-Id: I7f4f405fe1b2afd7b067146ab9c947312bb7d6fd
diff --git a/utils/omni_emulator/system.prop b/utils/omni_emulator/system.prop
new file mode 100644
index 0000000..81ad984
--- /dev/null
+++ b/utils/omni_emulator/system.prop
@@ -0,0 +1,2 @@
+# we are not caf
+sys.vendor.qti.servicetracker.disable=true