Android plugin experiment (duckduckgo#3434)

* Add plugin change experiment

* Move into being an experiment

* Lint fix

* Use add for patches as safer and simpler

Author: jonathanKingston

overrides/android-override.json

@@ -2509,6 +2509,71 @@
                     ]
                 }
             }
+        },
+        "apiManipulation": {
+            "readme": "Example config for apiManipulation to set navigator.plugins to return PDF viewer plugins",
+            "state": "enabled",
+            "exceptions": [],
+            "settings": {
+                "apiChanges": {},
+                "conditionalChanges": [
+                    {
+                        "condition": { "experiment": { "experimentName": "contentScopeExperiment0", "cohort": "treatment" } },
+                        "patchSettings": [
+                            {
+                                "op": "add",
+                                "path": "/apiChanges/Navigator.prototype.plugins",
+                                "value": {
+                                    "type": "descriptor",
+                                    "getterValue": {
+                                        "type": "array",
+                                        "value": [
+                                            {
+                                                "name": "PDF Viewer",
+                                                "filename": "internal-pdf-viewer",
+                                                "description": "Portable Document Format"
+                                            },
+                                            {
+                                                "name": "Chrome PDF Viewer",
+                                                "filename": "internal-pdf-viewer",
+                                                "description": "Portable Document Format"
+                                            },
+                                            {
+                                                "name": "Chromium PDF Viewer",
+                                                "filename": "internal-pdf-viewer",
+                                                "description": "Portable Document Format"
+                                            },
+                                            {
+                                                "name": "Microsoft Edge PDF Viewer",
+                                                "filename": "internal-pdf-viewer",
+                                                "description": "Portable Document Format"
+                                            },
+                                            {
+                                                "name": "WebKit built-in PDF",
+                                                "filename": "internal-pdf-viewer",
+                                                "description": "Portable Document Format"
+                                            }
+                                        ]
+                                    }
+                                }
+                            }
+                        ]
+                    }
+                ]
+            }
+        },
+        "contentScopeExperiments": {
+            "state": "enabled",
+            "features": {
+                "contentScopeExperiment0": {
+                    "state": "enabled",
+                    "minSupportedVersion": 52410000,
+                    "cohorts": [
+                        { "name": "control", "weight": 1 },
+                        { "name": "treatment", "weight": 1 }
+                    ]
+                }
+            }
         }
     },
     "unprotectedTemporary": [],