Upload files are broken depending on the docker image

Description:

If you use the rocketchat/rocket.chat:3.11.2 image, the upload files on the filesystem are not working at all. If you use rocket.chat:3.11.2 from docker everythings works fine.

Steps to reproduce:

1. Use rocketchat/rocket.chat:3.11.2
2. Start containers
3. View or upload an image

Expected behavior:

An uploaded image should be shown or be uploaded.

Actual behavior:

• If you want to upload, you get an access rights error.
• If you want to show an already uploaded image it is not showing.

Server Setup Information:

• Version of Rocket.Chat Server: 3.11.2
• Operating System: Ubuntu 18
• Deployment Method: docker
• Number of Running Instances: 14
• DB Replicaset Oplog: yes
• NodeJS Version: 12.18.4
• MongoDB Version: 4.0.22

Client Setup Information

• Desktop App or Browser Version: Firefox 86
• Operating System: Win 10

Additional context

Something in the image from rocket.chat team is broken. The same version, but from docker verified works fine.

Could impact: #20556, #20984 and #20640

Start by comparing the rocketchat/rocket.chat:3.11.2 and rocket.chat:3.11.2 Docker images, then reproduce upload and image viewing with the listed Ubuntu 18 and Docker setup. Done means filesystem uploads succeed without an access-rights error and previously uploaded images display correctly.