[Tiered Caching] Clear up disk cache data during node shutdown

[sgup432]

Is your feature request related to a problem? Please describe

As part of tiered caching, we introduced a disk tier(using ehcache underneath) which stores cache data under a specified path. During a node shutdown, we want to clear up the disk cache data as we are not looking to preserve it between restarts.

Describe the solution you'd like

Delete all the files and subdirectories under the specified path using IOUtils.rm(path).

Related component

Search:Performance

Describe alternatives you've considered

No response

Additional context

No response

[sgup432]

Issue fixed.