LibC++ hardening detected an out-of-bounds write in `testInitFromDataWithLeadingEmptyBytes`. The `std::string` initialized with "\0\0\0\0" was empty, making the access `addressString[3]` invalid.
Updated the `std::string` constructor to specify the size, so it correctly includes the null bytes, preventing the crash.
PiperOrigin-RevId: 846853226