Activity "created" field value is wrong

Problem/Motivation

Activity entity has created field that should contain the time when the entity was created. Instead, the field contain the time creation of the entity from field_activity_entity own field.

This leads to a few common problems:

• If the field_activity_entity entity created as unpublished a long time ago, after publishing related notification can be lost among others notifications (instead appearing on the top of the notifications list)
• created date of activity could have unexpected displaying (for example, if related entity is profile that created a few years ago

Proposed resolution

Make created field contain real activity creation time rather then related entity.

Remaining tasks

User interface changes

API changes

Data model changes