Enable post events analytics callback

[yanus]

I was trying to enable activity completion in Moodle with a BigBlueButton docker setup and found the following two problems:

1. The SHARED_SECRET isn't passed into the recordings container. This is easy to fix by adding the line in the docker compose file.
2. The post_events_analytics_callback.rb script expects the file /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties (https://github.com/bigbluebutton/bigbluebutton/blob/19c66908c45030c3c872a245063fa575f7e1bf9b/record-and-playback/core/scripts/post_events/post_events_analytics_callback.rb#L158), however this file doesn't exist in the recordings container. The script only really needs the SHARED_SECRET, which is overridden by /etc/bigbluebutton/bbb-web.properties, but it will fail if it can't find bigbluebutton.properties. As a temporary workaround, I can get it to work by copying bigbluebutton.properties from the bbb-web container. Edit: After looking at a related issue (#129), it seems that this might have to be fixed upstream, similar to this commit: https://github.com/bigbluebutton/bigbluebutton/commit/63dca7506ef2c17d12f2f61147d27fca9ad11383

[ben-ba]

-> close