DEVICE_NAME_SIZE macro
Device Name Characteristic: 1. For iOS, when it tries to get the value of Device Name Characteristic, the PDU "Read By Type Request" will be used, and the valid length of corresponding response is 19 (23 - 1 - 1 - 2). 2. For Android, when it tries to get the value of Device Name Characteristic, the PDU "Read Request" will be used, and the valid length of corresponding response is 22 (23 - 1).