Removing unnecessary Less vars, which are not in use any more.
Also slightly modifying code comment for better code style.
Change-Id: I6e2417561afb03225eaca99ea93135f975a51593
This is programmatic output from python3 scripts/migrate.py
This will result in a Minerva skin dependent on MobileFrontend.
Post merge we will rename message keys to have minerva- prefix
Bug: T166748
Change-Id: Iff1f7e63e796cc5d4a6d2ab0370e0c33248d2fce