Adjusted additional properties

Author: Auz

schemas/com.growthbook/experiment_viewed/jsonschema/1-0-0

@@ -24,8 +24,21 @@
     "hashValue": {
       "type": "string",
       "maxLength": 160
-    }
+    },
+    "custom": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "key": {
+            "type": "string"
+          },
+          "value": {
+            "type": ["string", "number", "integer", "null"]
+          }
+        }
+      }
+    },
   },
   "required": ["experimentId", "variationId"],
-  "additionalProperties": true
 }