This update lets the mail enterprise push notification component continue working on Ubuntu 20.04 systems that use an older approved cryptography package. It avoids forcing some internal systems to upgrade the operating system or install non-standard packages just to receive this module update.

A few internal systems are still running ubuntu 20.04 (focal) which ships with cryptography 2.8. The `backend` parameter was made optional (automatically falling back to the default backend) [in 3.1]. 

Provide a backend explicitly so the module can be updated without needing to upgrade the system (or install a non-distro package).

[in 3.1]: https://cryptography.io/en/3.4.2/changelog.html#v3-1

The system’s date and time library was updated to a newer version, with related adjustments in scheduling and timer areas. This helps keep the platform current and reduces the risk of issues from outdated internal components, without introducing a major visible change for users.

This commit contains adaptations regarding this change. See community counterpart.