Add 'added in' version

Co-authored-by: Hubert Chathi <hubertc@matrix.org>

data/event-schemas/schema/core-event-schema/call_event.yaml

@@ -16,6 +16,7 @@ properties:
     description: 'This identifies the party that sent this event. A client may
       choose to re-use the device ID from end-to-end cryptography for the value
       of this field.'
+    x-addedInMatrixVersion: "1.7"
 required:
 - call_id
 - version

data/event-schemas/schema/m.call.hangup.yaml

@@ -34,6 +34,9 @@ properties:
         description: Reason for the hangup. Note that this was optional in
           previous previous versions of the spec, so a missing value should be
           treated as `user_hangup`.
+        x-changedInMatrixVersion:
+          1.7: |-
+            Additional values were added.
         enum:
         - ice_timeout
         - ice_failed

data/event-schemas/schema/m.call.invite.yaml

@@ -35,6 +35,7 @@
                 "invitee": {
                     "type": "string",
                     "description": "The ID of the user being called. If omitted, any user in the room can answer.",
+                    "x-addedInMatrixVersion": "1.7",
                 }
             },
             "required": ["offer", "lifetime"]

data/event-schemas/schema/m.call.negotiate.yaml

@@ -33,6 +33,7 @@ description: |
   working with the WebRTC API and is mandatory. Receiving clients should not
   attempt to validate the `type` field, but simply pass the object into the
   WebRTC API.
+x-addedInMatrixVersion: "1.7"
 allOf:
 - "$ref": core-event-schema/room_event.yaml
 properties:

data/event-schemas/schema/m.call.reject.yaml

@@ -13,6 +13,7 @@ description: |
 
   Note that, unlike `m.call.hangup`, this event has no `reason` field: the rejection of
   a call is always implicitly because the user chose not to answer it.
+x-addedInMatrixVersion: "1.7"
 allOf:
 - "$ref": core-event-schema/room_event.yaml
 properties: