Author: Zig Tan
MDL-61881 report_stats: Implement null privacy provider
http://git.moodle.org/gw?p=moodle.git;a=commit;h=737ab6eff805e8a8e902fdd6252858373abcccd2
http://github.com/moodle/moodle/commit/737ab6eff805e8a8e902fdd6252858373abcccd2
+ 3.3 en [privacy:metadata,report_stats]