Webform Submissions should respect syncing status

Problem/Motivation

Webform submissions are setting their changed timestamp in their presave method to the current timestamp.

Why is that? AFAICT the field is a ChangedItem and that has that functionality builtin (and it respects isSyncing).

But if that method stays in place there's this issue with it: It sets the changed timestamp unconditionally instead of respecting the flag isSyncing (from the SynchronizableEntityTrait you are using, via ContentEntityBase).

Synchronization processes (like for example the importer from default_content_deploy) want to save data as-is,
so that the data in the system being deployed to will be the same as the one exported from the source system.

What's more: Especially the changed date is important, because it is used for optimizing the sync processes and for preventing sync loops.

Proposed resolution

One simple way to solve this would be to wrap the line in an if.