Support "TZ" environment variable in docker container

**Is your feature request related to a problem? Please describe.**
The docker container does not use the environment variable `TZ` .

**Describe the solution you'd like**
If I set the environment variable `TZ` for a docker container, CC should use that time zone instead of the default `UTC`.

**Describe alternatives you've considered**
None

**Additional context**
Most of the docker image maintainers consider the environment variable `TZ` as the required time zone.

Jira issue: CRDB-36146

No files or tests are named in the issue. Start by locating the Docker image configuration and the code that selects the default UTC time zone, then verify a container with TZ set uses that zone while one without it retains UTC; run the relevant container or integration tests if available.

Written by the indexing model from the issue text.