Clarify the message lengths

Author: PaulZC

src/u-blox_GNSS.cpp

@@ -8952,7 +8952,7 @@ bool DevUBLOXGNSS::getUniqueChipId(UBX_SEC_UNIQID_data_t *data, uint16_t maxWait
     data->uniqueId[i] = extractByte(&packetCfg, i + 4);
 
   // The ID is five bytes on the F9 and M9 (version 1) but six bytes on the M10 (version 2)
-  if ((data->version == 2) && (packetCfg.len == 10))
+  if ((data->version == 2) && (packetCfg.len == UBX_SEC_UNIQID_LEN_VERSION2))
     data->uniqueId[5] = extractByte(&packetCfg, 9);
   else
     data->uniqueId[5] = 0;

src/u-blox_structs.h

@@ -2035,7 +2035,8 @@ typedef struct
 
 // UBX-SEC-UNIQID (0x27 0x03): Unique chip ID
 // The ID is five bytes on the F9 and M9 (version 1) but six bytes on the M10 (version 2)
-const uint16_t UBX_SEC_UNIQID_LEN = 9;
+const uint16_t UBX_SEC_UNIQID_LEN_VERSION1 = 9;
+const uint16_t UBX_SEC_UNIQID_LEN_VERSION2 = 10;
 
 typedef struct
 {