Apply the amplification limit for all packets, not just handshake packets in ietf quic. also fixes an issue where shouldgeneratepacket doesn't check if the connection is connected. protected by gfe2_reloadable_flag_quic_move_amplification_limit. Because of lack of cert compression, set anti_amplification_factor to 5. This change is from pending cl/313200305. PiperOrigin-RevId: 313595976 Change-Id: Ia67e8c8faa6c17ebc682318047dc8996df55715f