gfe-relnote: (n/a) In quic_framer_process_data_packet_fuzzer, set framer's decrypter for INITIAL encryption level. Test only.

This is needed to default enable --gfe2_reloadable_flag_quic_framer_doesnt_create_initial_encrypter in cl/275513312.

PiperOrigin-RevId: 275528736
Change-Id: I943ff1a2775f690c9c8338ca00632191b0f0257d

quic/test_tools/fuzzing/quic_framer_process_data_packet_fuzzer.cc

diff --git a/quic/test_tools/fuzzing/quic_framer_process_data_packet_fuzzer.cc b/quic/test_tools/fuzzing/quic_framer_process_data_packet_fuzzer.cc
index db6f7a2..44dc275 100644
--- a/quic/test_tools/fuzzing/quic_framer_process_data_packet_fuzzer.cc
+++ b/quic/test_tools/fuzzing/quic_framer_process_data_packet_fuzzer.cc
@@ -150,6 +150,12 @@
           level, std::make_unique<NullDecrypter>(framer->perspective()));
     }
   }
+
+  if (!framer->version().KnowsWhichDecrypterToUse()) {
+    framer->SetDecrypter(
+        quic::ENCRYPTION_INITIAL,
+        std::make_unique<NullDecrypter>(framer->perspective()));
+  }
 }
 
 class FuzzingFramerVisitor : public NoOpFramerVisitor {