Reduce the high/low MTU discovery targets to 1400 & 1380 bytes.

PiperOrigin-RevId: 394516336

quic/core/quic_mtu_discovery.h

diff --git a/quic/core/quic_mtu_discovery.h b/quic/core/quic_mtu_discovery.h
index b16cc6a..dddd33d 100644
--- a/quic/core/quic_mtu_discovery.h
+++ b/quic/core/quic_mtu_discovery.h
@@ -27,9 +27,9 @@
 static_assert(kPacketsBetweenMtuProbesBase < (1 << 8),
               "The initial number of packets between MTU probes is too high");
 
-// The incresed packet size targeted when doing path MTU discovery.
-const QuicByteCount kMtuDiscoveryTargetPacketSizeHigh = 1450;
-const QuicByteCount kMtuDiscoveryTargetPacketSizeLow = 1430;
+// The increased packet size targeted when doing path MTU discovery.
+const QuicByteCount kMtuDiscoveryTargetPacketSizeHigh = 1400;
+const QuicByteCount kMtuDiscoveryTargetPacketSizeLow = 1380;
 
 static_assert(kMtuDiscoveryTargetPacketSizeLow <= kMaxOutgoingPacketSize,
               "MTU discovery target is too large");