[autotest] Use |json| instead of |simplejson|.

simplejson was moved into the library as of python 2.4. We're now at
python 2.6/2.7, and having to keep installing simplejson everywhere has
slowly turned into a hassle.  Since we can just trivially drop/rename
it, let's do so.

The rpc_interface parts of this change have been vetted, the rest is
done just as a s/simplejson/json/ across the code, which afaik should be
a safe thing to do.

BUG=None
TEST=unit, run_suite
DEPLOY=apache

Change-Id: Iab35f71157e7e5cd3be5291c776b07eb3283be8e
Reviewed-on: https://gerrit.chromium.org/gerrit/46424
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
diff --git a/frontend/shared/resource_test_utils.py b/frontend/shared/resource_test_utils.py
index 8cb742f..f52cd3b 100644
--- a/frontend/shared/resource_test_utils.py
+++ b/frontend/shared/resource_test_utils.py
@@ -1,5 +1,5 @@
 import operator, unittest
-import simplejson
+import json
 from django.test import client
 from autotest_lib.frontend.afe import frontend_test_utils, models as afe_models
 
@@ -53,7 +53,7 @@
         if 'data' in kwargs:
             kwargs.setdefault('content_type', 'application/json')
             if kwargs['content_type'] == 'application/json':
-                kwargs['data'] = simplejson.dumps(kwargs['data'])
+                kwargs['data'] = json.dumps(kwargs['data'])
 
         if uri.startswith('http://'):
             full_uri = uri
@@ -72,7 +72,7 @@
             return response.content
 
         try:
-            return simplejson.loads(response.content)
+            return json.loads(response.content)
         except ValueError:
             self.fail('Invalid reponse body: %s' % response.content)