[SPARK-19740][MESOS] Add support in Spark to pass arbitrary parameters into docker when running on mesos with docker containerizer

## What changes were proposed in this pull request?

Allow passing in arbitrary parameters into docker when launching spark executors on mesos with docker containerizer tnachen

## How was this patch tested?

Manually built and tested with passed in parameter

Author: Ji Yan <jiyan@Jis-MacBook-Air.local>

Closes #17109 from yanji84/ji/allow_set_docker_user.