[Telemetry] Move telemetry/examples to telemetry/experimental.

This is so that we can use the telemetry/examples folder for putting an examples
end to end benchmark.

BUG=482227

Review URL: https://codereview.chromium.org/1111103002

Cr-Commit-Position: refs/heads/master@{#330629}

tools/telemetry/examples/credentials_example.json

@@ -2,7 +2,7 @@
   "google": {
     "username": "<your google account here>",
     "password": "<your google password here>"
-  }
+  },
   "facebook": {
     "username": "<your google account here>",
     "password": "<your google password here>"

tools/telemetry/examples/list_available_browsers

-#!/usr/bin/env python
-# Copyright (c) 2012 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import os
-import sys
-
-sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir))
-
-from telemetry.core import browser_options
-
-
-def Main(args):
-  options = browser_options.BrowserFinderOptions()
-  options.browser_type = 'list'
-  parser = options.CreateParser('list_available_browsers')
-  parser.parse_args()
-  return 0
-
-
-if __name__ == '__main__':
-  sys.exit(Main(sys.argv[1:]))