async onBootDevice(event) {
    Object.assign(this.context, {
      deviceId: event.deviceId,
    });
  }
Hook that is supposed to be called from device.boot()

@protected
@async
@param {Object} event - Device boot event object
@param {string} event.deviceId - Current deviceId
@param {boolean} event.coldBoot - true, if the device gets turned on from the shutdown state.
@return {Promise<void>} - when done