This parameter determines how long time passed from either connection or CCCD write (depending on the value used for start_on_notify_cccd_handle) it will take before a Connection Parameter Update Request is sent, if the initial connection parameters of the Central are not within the Peripheral's requirements.
If the start_on_notify_cccd_handle is set to BLE_GATT_HANDLE_INVALID, the time will be measured from the CONNECTED event. If the start_on_notify_cccd_handle is set to the value of a CCCD, time will be measured from that specific CCCD is written by the GATT Client.
