MDL-41283 report_participation: Added phpdoc about function not used

In new logging api, xxx_get_view_actions() and xxx_get_post_actions()
will not be used to identify the paticipation of user. Event's crud
and edulevel status will define user's participation.

mod/data/lib.php

@@ -1722,7 +1722,12 @@ function data_print_ratings($data, $record) {
 }
 
 /**
- * For Participantion Reports
+ * List the actions that correspond to a view of this module.
+ * This is used by the participation report.
+ *
+ * Note: This is not used by new logging system. Event with
+ *       crud = 'r' and edulevel = LEVEL_PARTICIPATING will
+ *       be considered as view action.
  *
  * @return array
  */
@@ -1731,6 +1736,13 @@ function data_get_view_actions() {
 }
 
 /**
+ * List the actions that correspond to a post of this module.
+ * This is used by the participation report.
+ *
+ * Note: This is not used by new logging system. Event with
+ *       crud = ('c' || 'u' || 'd') and edulevel = LEVEL_PARTICIPATING
+ *       will be considered as post action.
+ *
  * @return array
  */
 function data_get_post_actions() {