Fixed Experiment Name

crrev.com/c/1055647 had an experiment name mixed up with the study
name, fixing that.

Change-Id: Id140d3aff38f2e96ae279651bcd3709cd4278114
Reviewed-on: https://chromium-review.googlesource.com/1055686Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Carlos IL <carlosil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557998}

testing/variations/fieldtrial_testing_config.json

@@ -739,7 +739,7 @@
             ],
             "experiments": [
                 {
-                    "name": "BundledConnectionHelpEnabled",
+                    "name": "HTTPHelpCenterEnabled",
                     "enable_features": [
                         "BundledConnectionHelp"
                     ]