Update personal info experiment to field trial config.

This is required for cl/336785311

Bug: 1137621
Change-Id: I099244a1f754955969b68b3c6478fb72e4b99db9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2473617Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Jing Wang <jiwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818338}

testing/variations/fieldtrial_testing_config.json

@@ -558,7 +558,7 @@
             ],
             "experiments": [
                 {
-                    "name": "Enabled_20200917",
+                    "name": "Enabled_20201015",
                     "enable_features": [
                         "AssistPersonalInfo",
                         "AssistPersonalInfoAddress",