Action Result
The client's report of a device action, sent with A2aSession.sendActionResult. It mirrors ActionResult in payloads.proto.
The action id is sent as action_id (the field name in payloads.proto) and is always ACTION_ID; the server has agreed to this fixed value for now.
Parameters
success
true when the device action succeeded, false otherwise.
outcome
free-form label such as OK, PLAYING or DISPLAYED; the server does not validate it.
message
optional detail for debugging and logs only.