When HAP reconnect, it sends indication of all events that happen during
the disconnection.
But it should wait for the profile to be ready and for the MTU to have
been negotiated or else the remote may not be ready yet.
As a side effect of this, the current GattServer doesn't re-populate the
handle of subscriber during a reconnection, we have to bypass this check
to send the notification
HAS can be run in synchronized mode, requiring a server to be able to
communicate with another CL.
This CL is doing a quick implementation of such functionality for preset
selection.
