Add Field Trial Testing Config for IsolatePasswordSites on Android.

Bug: 905513
Change-Id: Ide18c23965aa99634fc22cdea1a319c4df01f29a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1733647Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Steven Holte <holte@chromium.org>
Auto-Submit: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684186}

testing/variations/fieldtrial_testing_config.json

@@ -2739,6 +2739,21 @@
             ]
         }
     ],
+    "IsolatePasswordSites": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "site-isolation-for-password-sites"
+                    ]
+                }
+            ]
+        }
+    ],
     "JankTrackingSweepLine": [
         {
             "platforms": [