applications: nrf_desktop: Improve USB suspend in BLE conn params

Change improves USB suspend handling in BLE conn params module. The
connection parameters are updated back to defaults when USB cable is
disconnected. This is done to make the behavior more consistent (longer
connection intervals are used only while USB is suspended) and to speed
up sending HID reports when USB is reconnected in case dongle has an
external power supppy (e.g. DK acting as a dongle).

Jira: NCSDK-30261

Signed-off-by: Marek Pieta <[email protected]>

Author: MarekPieta

applications/nrf_desktop/src/modules/ble_conn_params.c

@@ -242,6 +242,7 @@ static void usb_state_event_handler(enum usb_state new_state)
 		usb_suspended = true;
 		break;
 
+	case USB_STATE_DISCONNECTED:
 	case USB_STATE_ACTIVE:
 		usb_suspended = false;
 		break;