ble_gap_adv_stop() function

Stops the currently-active advertising procedure. A success return code indicates that advertising has been fully aborted and a new advertising procedure can be initiated immediately. NOTE: If the caller is running in the same task as the NimBLE host, or if it is running in a higher priority task than that of the host, care must be taken when restarting advertising. Under these conditions, the following is *not* a reliable method to restart advertising: ble_gap_adv_stop() ble_gap_adv_start() Instead, the call to `ble_gap_adv_start()` must be made in a separate event context. That is, `ble_gap_adv_start()` must be called asynchronously by enqueueing an event on the current task's event queue. See https://github.com/apache/mynewt-nimble/pull/211 for more information.