When pc-ble-driver-py was used on central side for initiating LE
Secure Connections pairing against peripheral which does not support
LE SC, pairing timed out because pc-ble-driver-py was waiting for
event gap_evt_lesc_dhkey_request.
Fix is to expect BLEEvtID.gap_evt_lesc_dhkey_request only when both
of the devices support LE Secure Connections.
When pc-ble-driver-py was used on central side for initiating LE Secure Connections pairing against peripheral which does not support LE SC, pairing timed out because pc-ble-driver-py was waiting for event gap_evt_lesc_dhkey_request.
Fix is to expect BLEEvtID.gap_evt_lesc_dhkey_request only when both of the devices support LE Secure Connections.