Backend crashes when using docker

[oysand]

Describe the bug
When running Flotilla using docker the backend crashes. It seem that the app does not have permission to read '/app/.IdentityService'.

To Reproduce
Run the following command: docker-compose up --build backend

Expected behavior
The backend should be able to run when running in docker.

Screenshots

[GodVenn]

This is most likely an issue with the usage of DefaultAzureCredentials as the credential handler for the backend, and we are surely not the first to encounter this issue so there is probably an easy fix to this.