Minor Description
There is lacking of a method to get all folders and files with sort of specified storage policy via command line, like ALL_SSD type.
By adding storage policy id to oiv output, it will help with oiv post-analysis to have a overview of all folders/files with specified storage policy and to apply internal regulation based on this information.
Currently, for PBImageXmlWriter.java, in HDFS-9835 it added function to print out xattr which including storage policy already.