Dev: Include JDK in base image

**Describe the task**
Currently this is installed in the API image, we could bake it into the base image as it's unchanging app wise, or we could completely remove it if it's only used for redapp tests

**Acceptance Criteria**
- [ ] JDK is included in base image or removed altogether

**Additional context**
- Add any other context about the task here.
- Or here

No files or tests are named. Start by locating the API and base image definitions, then determine whether the JDK is needed for redapp tests; done means the JDK is included in the base image or removed entirely, with the acceptance criterion checked.

Written by the indexing model from the issue text.