[SPARK-18160][CORE][YARN] spark.files & spark.jars should not be passed to driver in yarn mode

## What changes were proposed in this pull request?

spark.files is still passed to driver in yarn mode, so SparkContext will still handle it which cause the error in the jira desc.

## How was this patch tested?

Tested manually in a 5 node cluster. As this issue only happens in multiple node cluster, so I didn't write test for it.

Author: Jeff Zhang <zjffdu@apache.org>

Closes #15669 from zjffdu/SPARK-18160.