Remove NTP timestamp from PacketBuffer::Packet.

Bug: webrtc:12579
Change-Id: I64ca0ddb6f5c20bef5e9503955e0e4b4c484a1e7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/211662
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33448}

modules/video_coding/packet_buffer.cc

@@ -37,13 +37,11 @@ namespace video_coding {
 
 PacketBuffer::Packet::Packet(const RtpPacketReceived& rtp_packet,
                              const RTPVideoHeader& video_header,
-                             int64_t ntp_time_ms,
                              int64_t receive_time_ms)
     : marker_bit(rtp_packet.Marker()),
       payload_type(rtp_packet.PayloadType()),
       seq_num(rtp_packet.SequenceNumber()),
       timestamp(rtp_packet.Timestamp()),
-      ntp_time_ms(ntp_time_ms),
       times_nacked(-1),
       video_header(video_header),
       packet_info(rtp_packet.Ssrc(),