Improve local testcontainer startup to avoid overriding running main docker db instance

[ianliuwk1019]

Describe the task When running backend tests locally the testcontainer needs start up a new test database and it removes/overrides the existing database container if the developer also has one running. The side effect is annoying and makes it inconvenient for developing locally for developers.

Acceptance Criteria

• [ ] Make adjustment so that testcontainer does not remove the main db container when testing.
• [ ] Tests still run successfully locally.
• [ ] Pipeline still runs tests successfully.

Additional context

• Add any other context about the task here.