Add fieldtrial testing config for DecoupleSyncFromAndroidMasterSync

Bug: 1105795
Change-Id: Idd7efc38c149769b837fced9743731f5eb0802a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2565129
Auto-Submit: Victor Vianna <victorvianna@google.com>
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#831844}

testing/variations/fieldtrial_testing_config.json

@@ -2055,6 +2055,21 @@
             ]
         }
     ],
+    "DecoupleSyncFromAndroidMasterSync": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled_20201130",
+                    "enable_features": [
+                        "DecoupleSyncFromAndroidMasterSync"
+                    ]
+                }
+            ]
+        }
+    ],
     "DeepScanningForAppUsers": [
         {
             "platforms": [