[Passwords] EnablePasswordGenerationForClearTextFields Testing Config

This change adds an entry for EnablePasswordGenerationForClearTextFields
to the testing/variations/fieldtrial_testing_config.json.

Bug: 1021897
Change-Id: I0e328629babc5f81c7bee05ea669598fd7ff69ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2543392
Auto-Submit: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Steven Holte <holte@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829071}

testing/variations/fieldtrial_testing_config.json

@@ -2703,6 +2703,27 @@
             ]
         }
     ],
+    "EnablePasswordGenerationForClearTextFields": [
+        {
+            "platforms": [
+                "android",
+                "android_webview",
+                "chromeos",
+                "ios",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "EnablePasswordGenerationForClearTextFields"
+                    ]
+                }
+            ]
+        }
+    ],
     "EnableSafetyTipUI": [
         {
             "platforms": [