RotationPeriodExponent: Indicates the nominal period between each rotation of the beacon's ephemeral ID. "Nominal" because the beacon should randomize the actual interval. See [the spec at github](https://github.com/google/eddystone/tree/master/eddystone-eid)
for details. This value corresponds to a power-of-two scaler on the
beacon's clock: when the scaler value is K, the beacon will begin broadcasting a new ephemeral ID on average every 2^K seconds.