[ib] fix docker env file write location

[tosterberg]

Description

Fix issue where env variables passed using IB are not being added to the container when running IB.

Current implementation will add the docker_env file to ./model/test relative to the current working directory, however, the docker_env needs to be in the same directory as the ./launch_container.sh when it is run in order to add the env variables to the container. Since the paths were already relative in the script I updated the file right to current working directory ./ rather than ./model/test