test-scripts: Deprecate flimflam.py

We are moving tests away from flimflam.py to using shill_proxy suite of scripts.
Add deprecate comments to flimflam.py to warn users, and to remind ourselves.

BUG=chromium:260312
TEST=None.

Change-Id: I62f3f6234b46a753e482f7f294c186d7fb2bf618
Reviewed-on: https://gerrit.chromium.org/gerrit/61907
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/test-scripts/flimflam.py b/test-scripts/flimflam.py
index d141c3f..3888f73 100755
--- a/test-scripts/flimflam.py
+++ b/test-scripts/flimflam.py
@@ -2,6 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+# DEPRECATED
+# Do not use flimflam.py in future development.
+# Extend / migrate to shill_proxy suite of scripts instead.
+
 import logging, time
 
 import dbus
@@ -22,6 +26,7 @@
 # to print properties returned via DBus
 #
 def convert_dbus_value(value, indent=0):
+    # DEPRECATED
     spacer = ' ' * indent
     if value.__class__ == dbus.Byte:
         return int(value)
@@ -45,6 +50,7 @@
         return str(value)
 
 class FlimFlam(object):
+    # DEPRECATED
 
     SHILL_DBUS_INTERFACE = "org.chromium.flimflam"
     UNKNOWN_METHOD = 'org.freedesktop.DBus.Error.UnknownMethod'
@@ -422,6 +428,7 @@
 
 
 class DeviceManager(object):
+    # DEPRECATED
     """Use flimflam to isolate a given interface for testing.
 
     DeviceManager can be used to turn off network devices that are not