Author: Sara Arjona
MDL-61958 core_rss: Implement privacy API
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7ce30dda42e87bab2c30b085afbfa7160b5f81f8
http://github.com/moodle/moodle/commit/7ce30dda42e87bab2c30b085afbfa7160b5f81f8
+ 3.3 en [privacy:metadata:user_private_key,core_rss]
+ 3.3 en [privacy:metadata:user_private_key:timecreated,core_rss]
+ 3.3 en [privacy:metadata:user_private_key:userid,core_rss]
+ 3.3 en [privacy:metadata:user_private_key:validuntil,core_rss]
+ 3.3 en [privacy:metadata:user_private_key:value,core_rss]