Support Container-based tests inherit Jenkins settings for git repos and branches

In our External tests, which are container-based tests, we set a new local environment inside the container different from jenkins host settings, since using default `get.sh` ([code link](https://github.com/adoptium/aqa-tests/blob/811cd61982cd075731389fe6c7a8500f3e8319a9/external/functional-test/test.sh#L32)). This caused problem in some situations, e.g. release JDK version doesn't match with openj9 master branch functional tests inside container. Several steps to support this:
- [ ] Pass git repos and branches in Jenkins parameters into docker
- [ ] update `get.sh` parameters to inherit Jenkins settings for git repos and branches ([code link](https://github.com/adoptium/aqa-tests/blob/811cd61982cd075731389fe6c7a8500f3e8319a9/external/functional-test/test.sh#L32))
- [ ] modify other `test.sh` files in external tests, similar as above step

Start with external/functional-test/test.sh, especially the linked get.sh invocation, and inspect the other test.sh files under external tests. Trace how Jenkins parameters reach the container and identify where repository and branch values are currently replaced. Done means container-based external tests inherit the Jenkins repository and branch settings consistently.

Written by the indexing model from the issue text.