Support to add multiple directory location for this property in server (pinot.server.instance.dataDir)

Hi,

Can we add multiple directory locations path to this below server conf property? @xiangfu0

pinot.server.instance.dataDir=
Like disk1 and disk2

So server chooses any one during runtime ...

Thanks
Akram Syed

Start by locating the server configuration handling for pinot.server.instance.dataDir and reviewing how a single directory is currently consumed. Determine the expected syntax and selection behavior for multiple paths, then add coverage for configuration parsing and runtime directory selection. Done means the server accepts multiple locations and selects one during runtime.

Written by the indexing model from the issue text.