set user's timezone information on the Backend.AI

## Motivation  

[Why is this Epic important? Clearly describe the context and reasons for creating this Epic.]  

- In the cloud environments, users may have multiple timezones.
- That case, we need to get the user’s timezone, store it, and inject the tinezone when the session runs

## Objective  

[What is the main goal of this Epic? Describe the desired outcome]  

-

## Expected Sub Issue

[Please list the subtasks you expect.]

-

JIRA Issue: BA-908