[midPoint-git] [Evolveum/midpoint] 6009f4: Fix "Clean up operation statistics" button

[mederly]

  Branch: refs/heads/master
  Home:   https://github.com/Evolveum/midpoint
  Commit: 6009f48ca5e6913ce384360c3bdbef9d43d0eec8
      https://github.com/Evolveum/midpoint/commit/6009f48ca5e6913ce384360c3bdbef9d43d0eec8
  Author: Pavol Mederly <mederly at evolveum.com>
  Date:   2021-07-07 (Wed, 07 Jul 2021)

  Changed paths:
    M gui/admin-gui/src/main/java/com/evolveum/midpoint/web/page/admin/server/PageTask.java
    M infra/schema/src/main/java/com/evolveum/midpoint/schema/statistics/ActivityStatisticsUtil.java

  Log Message:
  -----------
  Fix "Clean up operation statistics" button

Now it erases also statistics in the activity state tree.
(In a single task, currently.)

To review: changed PageTask.createDeleteItemDelta method.