Remove obsolete QUIC_BUG(quic_bug_5196).
Remove obsolete QUIC_BUG(quic_bug_5196).

This QUIC_BUG was added to provide more detailed debugging information. Now that we have root cause the issue, the QUIC_BUG can be removed so that the test with fixing flag being false would proceed to success (verified by set --test_arg='--gfe2_flip_all_feature_flags_to_true_for_test=true' and set quic_flush_pending_frames_and_padding_bytes_on_migration false ).

PiperOrigin-RevId: 406007363

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