[Passwords] Add PasswordScriptsFetching to field trial config

Bug: 1132230
Change-Id: Ief82359c2541d387cb2464c4ae7903075fb32275
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2432026
Auto-Submit: Maxim Kolosovskiy  <kolos@chromium.org>
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810805}

testing/variations/fieldtrial_testing_config.json

@@ -5267,6 +5267,21 @@
             ]
         }
     ],
+    "PasswordScriptsFetching": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "PasswordScriptsFetching"
+                    ]
+                }
+            ]
+        }
+    ],
     "PaymentRequestAlwaysAllowJustInTimePaymentApp": [
         {
             "platforms": [