[3.X.X][3.10.X] [3.11.0] Default channels are not displayed by default

Description:

I have defaulted 8 public channels so that they appear by default to users. This initially worked, but with versions 3.10 and 3.11 it no longer works. Even new users joining LDAP are forced to go to the channel directory to search, however the label is displayed which is a default channel.

Steps to reproduce:

1. Go to '/admin/rooms'
2. Click in the channels
3. Enable as default

Expected behavior:

When a user accesses the service, they will see the channels marked by default in their contact list.
New users will be members by default on these channels.

Actual behavior:

Channels marked as default are not displayed automatically in the left column

Server Setup Information:

• Version of Rocket.Chat Server:
• Operating System: Ubuntu
• Deployment Method: manual
• Number of Running Instances: 1
• DB Replicaset Oplog: Yes
• NodeJS Version: 12.18.0
• MongoDB Version: 4.0.21

Client Setup Information

Additional context

Relevant logs:

Start at the /admin/rooms channel settings flow and trace how a public channel marked as default is handled for existing and LDAP-created users. Reproduce the issue on the affected 3.10 or 3.11 versions, then verify that default channels appear in the contact list and that new users become members automatically.