Include debug_mode in the Public Metadata fingerprint.

PiperOrigin-RevId: 529141234
diff --git a/quiche/blind_sign_auth/blind_sign_auth.cc b/quiche/blind_sign_auth/blind_sign_auth.cc
index d13dc33..a0e9d95 100644
--- a/quiche/blind_sign_auth/blind_sign_auth.cc
+++ b/quiche/blind_sign_auth/blind_sign_auth.cc
@@ -284,6 +284,7 @@
       metadata.service_type(),
       OmitDefault(metadata.expiration().seconds()),
       OmitDefault(metadata.expiration().nanos()),
+      OmitDefault(metadata.debug_mode()),
   };
   const std::string input = absl::StrJoin(parts, "|");
   if (EVP_Digest(input.data(), input.length(),