Add encryption for contact sensor

[Rendarion]

Current Situation

Currently there is no known way to enable encryption for the contact sensor functions.

Proposed Change

If encryption is enabled, other parties can not read motion data and button press data. If encryption is enabled, other parties can not spoof door opening events, motion data and button press data

Additional Context

In case any events are used for sensitive actions, they may currently be spoofed. For example an alarm or camera my be turned off. Also currently motion sensor information my be gathered. It may be unwanted for privacy and home security reasons to broadcast this information publicly.

[NPohl]

I am also looking for this. In the BLE API there is a encryption mode mentioned, but I can't find any information how to enable it.