[SPARK-4994][network]Cleanup removed executors' ShuffleInfo in yarn shuffle service

when the application is completed, yarn's nodemanager can remove application's local-dirs.but all executors' metadata of completed application havenot be removed. now it lets yarn ShuffleService to have much more memory to store Executors' ShuffleInfo. so these metadata need to be removed.

Author: lianhuiwang <lianhuiwang09@gmail.com>

Closes #3828 from lianhuiwang/SPARK-4994 and squashes the following commits:

f3ba1d2 [lianhuiwang] Cleanup removed executors' ShuffleInfo