MB-6983: mark couch_docs_actual_disk_size as bytes stat too
MB-6983: mark couch_docs_actual_disk_size as bytes stat too

Change-Id: Ic70079826737c1734aae5f1ab26a2c753d68019b
Reviewed-on: http://review.couchbase.org/31504
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

mschoch/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,daverigby/ns_server,membase/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,daverigby/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,mschoch/ns_server,daverigby/ns_server,mschoch/ns_server,mschoch/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,membase/ns_server,t3rm1n4l/ns_server