Update Serial position (#959)

activities.json

@@ -1350,11 +1350,11 @@
     "description": "The Serial API provides a way for websites to read and write from a serial device through script. Such an API would bridge the web and the physical world, by allowing documents to communicate with devices such as microcontrollers, 3D printers, and other serial devices. There is also a companion explainer document.",
     "id": "webserial",
     "mozBugUrl": "https://bugzilla.mozilla.org/show_bug.cgi?id=webserial",
-    "mozPosition": "negative",
-    "mozPositionDetail": "Devices that offer serial interfaces often expose powerful, low-level functions over the interface with little or no authentication. Exposing that sort of capability to the web without adequate safeguards presents a significant threat to those devices.",
+    "mozPosition": "neutral",
+    "mozPositionDetail": "Devices that offer serial interfaces often expose powerful, low-level functions over the interface with little or no authentication. Exposing that sort of capability to the web without adequate safeguards presents a significant threat to those devices. A user deliberately installing a site-specific add-on may be adequate, given sufficiently understandable consent copy.",
     "mozPositionIssue": 336,
     "org": "Proposal",
-    "title": "Serial API",
+    "title": "Serial API (Add-On Gated)",
     "url": "https://wicg.github.io/serial"
   },
   {