Allow .well-known configuration to override key sharing mode

[jmartinesp]

Your use case

What would you like to do?

The home servers can add the configuration variable outbound_keys_pre_sharing_mode into io.element.e2ee in their /.well-known/matrix/client url so they can override how keys are shared in a room. As an example:

"io.element.e2ee": {
  "outbound_keys_pre_sharing_mode": "on_typing" // (on_room_opening, on_typing, disabled)
}

If this variable is not added, the default value in BuildConfig.outboundSessionKeySharingStrategy will be used.

Have you considered any alternatives?

No response

Additional context

No response

[bmarty]

disabled means that default will be used?

In OutboundSessionKeySharingStrategy, we also have the value WhenSendingEvent, which is the less effort, but still mandatory to be able to send a e2e Event.

[bmarty]

Ah there is a pre in outbound_keys_pre_sharing_mode, so that now clear for me. Please ignore me!