Rename quic::kMaxPacketSize to quic::kMaxOutgoingPacketSize

As part of cl/242197597, QUIC now has separate values for maximum incoming and outgoing packet sizes. This CL renames the constant to be clearer.

gfe-relnote: constant rename, no functional impact
PiperOrigin-RevId: 242708648
Change-Id: I3f440ba44b9c12394026116aaecdd2c166cc63b6
diff --git a/quic/core/chlo_extractor_test.cc b/quic/core/chlo_extractor_test.cc
index 57d8925..cea445d 100644
--- a/quic/core/chlo_extractor_test.cc
+++ b/quic/core/chlo_extractor_test.cc
@@ -99,7 +99,7 @@
   TestDelegate delegate_;
   QuicPacketHeader header_;
   std::unique_ptr<QuicEncryptedPacket> packet_;
-  char buffer_[kMaxPacketSize];
+  char buffer_[kMaxOutgoingPacketSize];
 };
 
 TEST_F(ChloExtractorTest, FindsValidChlo) {