Improve QuicFramer testing of retry
Improve QuicFramer testing of retry

This CL cleans up the server-side retry test to ensure it uses the correct packet for the version under test, and verifies that OnRetryPacket is appropriately called or not.

gfe-relnote: n/a, test-only
PiperOrigin-RevId: 292155834
Change-Id: I705f3ceb4336dfcdaaa795a0f69fc4114c74a321

google/quiche,google/quiche,google/quiche,google/quiche