Revert "Clean up last_packet_received_time_ as it's no longer used."

This reverts commit 2f4bc6416651be40ef8f95a4695e6b7c41f18666.

Reason for revert: Breaks downstream test

Original change's description:
> Clean up last_packet_received_time_ as it's no longer used.
>
> Bug: webrtc:15377
> Change-Id: I5453b9fd572a04dbea3241a2eb1c8ad8bb8b1186
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/320560
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Reviewed-by: Björn Terelius <terelius@webrtc.org>
> Commit-Queue: Ying Wang <yinwa@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#40792}

Bug: webrtc:15377
Change-Id: Ifa57671cc479cdd86f543c4edc236221beb76f90
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/321340
Auto-Submit: Björn Terelius <terelius@webrtc.org>
Reviewed-by: Ying Wang <yinwa@webrtc.org>
Owners-Override: Björn Terelius <terelius@webrtc.org>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40797}
diff --git a/call/rtp_transport_controller_send.h b/call/rtp_transport_controller_send.h
index 42f4f77..1aace1c 100644
--- a/call/rtp_transport_controller_send.h
+++ b/call/rtp_transport_controller_send.h
@@ -96,6 +96,7 @@
   absl::optional<Timestamp> GetFirstPacketTime() const override;
   void EnablePeriodicAlrProbing(bool enable) override;
   void OnSentPacket(const rtc::SentPacket& sent_packet) override;
+  void OnReceivedPacket(const ReceivedPacket& packet_msg) override;
 
   void SetSdpBitrateParameters(const BitrateConstraints& constraints) override;
   void SetClientBitratePreferences(const BitrateSettings& preferences) override;