Allow Cast certificates to have serial numbers greater than 20 bytes.

net/cert/internal/parse_certificate_fuzzer.cc

Index: net/cert/internal/parse_certificate_fuzzer.cc
diff --git a/net/cert/internal/parse_certificate_fuzzer.cc b/net/cert/internal/parse_certificate_fuzzer.cc
index e564c9b27bf8298dd698aba46a0bb04c3bd3ff3a..5efcd6fc20e66fbcb2dc66de819920d2276ba748 100644
--- a/net/cert/internal/parse_certificate_fuzzer.cc
+++ b/net/cert/internal/parse_certificate_fuzzer.cc
@@ -39,10 +39,9 @@ void ParseCertificateForFuzzer(const der::Input& in) {
       SignatureAlgorithm::CreateFromDer(signature_algorithm_tlv));
 
   ParsedTbsCertificate tbs;
-  if (!ParseTbsCertificate(tbs_certificate_tlv, &tbs))
+  if (!ParseTbsCertificate(tbs_certificate_tlv, {}, &tbs))
     return;
 
-  ignore_result(VerifySerialNumber(tbs.serial_number));
   RDNSequence subject;
   ignore_result(ParseName(tbs.subject_tlv, &subject));