gfe-relnote: Introduce QUIC_VERSION_50, protected by quic_enable_version_50

Version 50 uses header protection, initial obfuscators, and IETF IV construction.

PiperOrigin-RevId: 273780903
Change-Id: I2750db51f2a6e30d93ab52e9978129353134e5ee
diff --git a/quic/core/quic_packet_creator_test.cc b/quic/core/quic_packet_creator_test.cc
index 75ea7f5..075b5b4 100644
--- a/quic/core/quic_packet_creator_test.cc
+++ b/quic/core/quic_packet_creator_test.cc
@@ -343,6 +343,10 @@
         EXPECT_CALL(framer_visitor_, OnStreamFrame(_));
         EXPECT_CALL(framer_visitor_, OnStreamFrame(_));
       }
+      if (client_framer_.version().HasHeaderProtection()) {
+        EXPECT_CALL(framer_visitor_, OnPaddingFrame(_))
+            .Times(testing::AnyNumber());
+      }
       EXPECT_CALL(framer_visitor_, OnPacketComplete());
     }
     ProcessPacket(serialized);