Add kAFF2 enabling the sending of AckFrequencyFrame upon handshake completion.

Protected by FLAGS_quic_reloadable_flag_quic_can_send_ack_frequency.

PiperOrigin-RevId: 337855733
Change-Id: I45e3c11605e37c01e217a7a86237f35cdfb806c9
diff --git a/quic/core/quic_constants.h b/quic/core/quic_constants.h
index a1126c0..01ec240 100644
--- a/quic/core/quic_constants.h
+++ b/quic/core/quic_constants.h
@@ -120,7 +120,7 @@
 
 // Default minimum delayed ack time, in ms (used only for sender control of ack
 // frequency).
-const uint32_t kDefaultMinAckDelayTimeMs = 1;
+const uint32_t kDefaultMinAckDelayTimeMs = 5;
 
 // Default shift of the ACK delay in the IETF QUIC ACK frame.
 const uint32_t kDefaultAckDelayExponent = 3;