PURPOSE
Currently, there is an on-change to set an activity summary to the default
summary of an activity type. This can be useful if types are properly
configured. The problem is, the activity summary will be updated even if there
isn't any default summary on the type. Meaning that it simply removing a
relevant custom summary the user might have already entered.
SPECIFICATIONS
When triggering the on-change on activity_type_id, only update the activity
summary to the default summary if there is a default summary defined on the
activity type.
LINKS
Task-2254825
PR #51373
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>