The advInterval shall be an integer multiple of 0.625 ms in the range of 20 ms
to 10.24 s. If the advertising event type is either a discoverable undirected
//event type or a non-connectable undirected event type, the advInterval shall
//not be less than 100 ms. If the advertising event type is a connectable undirected
//event type, the advInterval can be 20 ms or greater.