Fixed it in 8e54481 of feature/branch-source branch. There is an inconsistency in gitlab4j.
One method = `getFileInfo` took params in the sequence -> project, path, commit hash
Second method = `getRawFile` took params in the sequence -> project, commit hash, path
So I was mistaken to use the first method param sequence for second method which resulted in `Commit Not Found` exception. Now SCM API do not need to perform heavy checkout which helps in faster branch builds.