update API descriptions

etc/api/chat/v1/chat-api.json

@@ -317,7 +317,7 @@
             }
         }
     }, 
-    "revision": "20200405", 
+    "revision": "20200701", 
     "rootUrl": "https://chat.googleapis.com/", 
     "schemas": {
         "ActionParameter": {
@@ -963,15 +963,23 @@
             "id": "Space", 
             "properties": {
                 "displayName": {
-                    "description": "Output only. The display name (only if the space is a room).", 
+                    "description": "Output only. The display name (only if the space is a room).\nPlease note that this field might not be populated in direct messages\nbetween humans.", 
                     "type": "string"
                 }, 
                 "name": {
                     "description": "Resource name of the space, in the form \"spaces/*\".\n\nExample: spaces/AAAAMpdlehYs", 
                     "type": "string"
                 }, 
+                "singleUserBotDm": {
+                    "description": "Whether the space is a DM between a bot and a single human.", 
+                    "type": "boolean"
+                }, 
+                "threaded": {
+                    "description": "Whether the messages are threaded in this space.", 
+                    "type": "boolean"
+                }, 
                 "type": {
-                    "description": "Output only. The type of a space.", 
+                    "description": "Output only. The type of a space.\nThis is deprecated. Use `single_user_bot_dm` instead.", 
                     "enum": [
                         "TYPE_UNSPECIFIED", 
                         "ROOM", 
@@ -979,7 +987,7 @@
                     ], 
                     "enumDescriptions": [
                         "", 
-                        "A chat space where memberships are free to change. Messages in rooms are\nthreaded.", 
+                        "Multi-user spaces such as rooms and DMs between humans.", 
                         "1:1 Direct Message between a human and a bot, where all messages are\nflat."
                     ], 
                     "type": "string"