fix(emqx_bridge_mongodb): use correct config when calling downgrade_type

Also limit result in mongodb ..._to_bridge_v1_config to not include more fields
than what's in the schema (most notably `description`).

apps/emqx_bridge/src/emqx_bridge_api.erl

@@ -913,7 +913,7 @@ format_resource(
     redact(
         maps:merge(
             RawConfFull#{
-                type => downgrade_type(Type, RawConf),
+                type => downgrade_type(Type, emqx_bridge_lib:get_conf(Type, BridgeName)),
                 name => maps:get(<<"name">>, RawConf, BridgeName),
                 node => Node
             },

apps/emqx_bridge/src/emqx_bridge_lib.erl

@@ -18,7 +18,8 @@
 -export([
     maybe_withdraw_rule_action/3,
     upgrade_type/1,
-    downgrade_type/2
+    downgrade_type/2,
+    get_conf/2
 ]).
 
 %% @doc A bridge can be used as a rule action.

apps/emqx_bridge_mongodb/src/emqx_bridge_mongodb_action_info.erl

@@ -26,19 +26,21 @@
 
 -define(SCHEMA_MODULE, emqx_bridge_mongodb).
 
-connector_action_config_to_bridge_v1_config(ConnectorConfig, ActionConfig) ->
-    fix_v1_type(
-        maps:merge(
+connector_action_config_to_bridge_v1_config(
+    #{<<"parameters">> := #{<<"mongo_type">> := MongoType}} = ConnectorConfig,
+    ActionConfig
+) ->
+    MergedConfig =
+        emqx_utils_maps:deep_merge(
             maps:without(
                 [<<"connector">>],
                 emqx_utils_maps:unindent(<<"parameters">>, ActionConfig)
             ),
             emqx_utils_maps:unindent(<<"parameters">>, ConnectorConfig)
-        )
-    ).
-
-fix_v1_type(#{<<"mongo_type">> := MongoType} = Conf) ->
-    Conf#{<<"type">> => v1_type(MongoType)}.
+        ),
+    BridgeV1Type = v1_type(MongoType),
+    BridgeV1Keys = schema_keys(BridgeV1Type),
+    maps:with(BridgeV1Keys, MergedConfig).
 
 bridge_v1_config_to_action_config(BridgeV1Config, ConnectorName) ->
     ActionTopLevelKeys = schema_keys(mongodb_action),