Merge pull request #16634 from neha-ojha/wip-default-device-class

osd: add default_device_class to metadata

Reviewed-by: xie xingguo <xie.xingguo@zte.com.cn>
Reviewed-by: Sage Weil <sage@redhat.com>

src/osd/OSD.cc

@@ -5880,6 +5880,7 @@ void OSD::_collect_metadata(map<string,string> *pm)
   // backend
   (*pm)["osd_objectstore"] = store->get_type();
   (*pm)["rotational"] = store_is_rotational ? "1" : "0";
+  (*pm)["default_device_class"] = store->get_default_device_class();
   store->collect_metadata(pm);
 
   collect_sys_info(pm, cct);