Update personal info experiment to field trial config.

This is required for cl/331929527

Bug: 1114538
Change-Id: I13bd5b627f90b060cea4cd4529e63969f1ff0bfb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2413722Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Jing Wang <jiwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808768}

testing/variations/fieldtrial_testing_config.json

@@ -546,9 +546,13 @@
             ],
             "experiments": [
                 {
-                    "name": "AssistPersonalInfo",
+                    "name": "Enabled_20200917",
                     "enable_features": [
-                        "AssistPersonalInfo"
+                        "AssistPersonalInfo",
+                        "AssistPersonalInfoAddress",
+                        "AssistPersonalInfoEmail",
+                        "AssistPersonalInfoName",
+                        "AssistPersonalInfoPhoneNumber"
                     ]
                 }
             ]