Outbound integration channel_id incorrect

Description:

Outbound integration requests for messages sent in direct chats contain an unusable channel_id.

Steps to reproduce:

1. Enable an outbound integration for all_direct_messages.
2. Send a message in a direct chat
3. Observe the payload sent by the integration - esp. the channel_id parameter. Example:

{ "bot":false, "channel_id": "97wAfJEuMGc5iDPZ2vrByxjuPoWLJS8EaB", "user_id": "97wAfJEuMGc5iDPZ2", "user_name": "mossy", "text": "Hiya" }

4. Attempt to use the channel_id from this payload in another API call, such as /api/v1/channels.members?roomId=97wAfJEuMGc5iDPZ2vrByxjuPoWLJS8EaB. The room ID is reported as invalid.
   Example:

{
    "success": false,
    "error": "The required \"roomId\" or \"roomName\" param provided does not match any channel [error-room-not-found]",
    "errorType": "error-room-not-found"
}

Expected behavior:

The channel_id from the webhook payload should be usable to retrieve the channel of the direct chat message.

Actual behavior:

The channel_id is invalid.

Server Setup Information:

• Version of Rocket.Chat Server: 3.15.0
• Operating System: Whatever the docker image uses, the host is Arch Linux
• Deployment Method: docker
• Number of Running Instances: 1
• DB Replicaset Oplog: enabled (I don't know what this means)
• NodeJS Version: v12.22.1
• MongoDB Version: 4.0.25 / mmapv1 (oplog Enabled)

Client Setup Information

• Desktop App or Browser Version: API issue
• Operating System: Arch Linux

Additional context

Relevant logs:

Exception while invoking method getRoomByTypeAndName Error: Invalid room [error-invalid-room]     at MethodInvocation.getRoomByTypeAndName (server/publications/room/index.js:51:10)     at MethodInvocation.methodsMap.<computed> (app/lib/server/lib/debug.js:76:34)     at maybeAuditArgumentChecks (packages/ddp-server/livedata_server.js:1771:12)     at packages/ddp-server/livedata_server.js:1689:15     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1234:12)     at packages/ddp-server/livedata_server.js:1687:36     at new Promise (<anonymous>)     at Server.applyAsync (packages/ddp-server/livedata_server.js:1686:12)     at Server.apply (packages/ddp-server/livedata_server.js:1625:26)     at Server.call (packages/ddp-server/livedata_server.js:1607:17)     at Object.post (app/api/server/v1/misc.js:263:26)     at app/api/server/api.js:394:82     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1234:12)     at Object._internalRouteActionHandler [as action] (app/api/server/api.js:394:39)     at Route.share.Route.Route._callEndpoint (packages/nimble_restivus/lib/route.coffee:150:32)     at packages/nimble_restivus/lib/route.coffee:59:33     at packages/simple_json-routes.js:98:9  => awaited here:     at Promise.await (/app/bundle/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/promise_server.js:60:12)     at Server.apply (packages/ddp-server/livedata_server.js:1638:22)     at Server.call (packages/ddp-server/livedata_server.js:1607:17)     at Object.post (app/api/server/v1/misc.js:263:26)     at app/api/server/api.js:394:82     at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1234:12)     at Object._internalRouteActionHandler [as action] (app/api/server/api.js:394:39)     at Route.share.Route.Route._callEndpoint (packages/nimble_restivus/lib/route.coffee:150:32)     at packages/nimble_restivus/lib/route.coffee:59:33     at packages/simple_json-routes.js:98:9 

Reproduce the outbound integration request for a direct-chat message, then trace the channel lookup through the integration payload code and the room/API paths shown in server/publications/room/index.js and app/api/server/v1/misc.js. Done means the emitted channel_id is accepted by channels.members and identifies the direct-chat room.