Move kFeedbackMessageType from Remb to Psfb

The FMT 15 is not specific only to REMB or loss notification messages.
Rather, it is the Application Layer FB (AFB) of Psfb (Payload Specific
Feedback Messages).
See https://tools.ietf.org/html/rfc4585#section-6.3

TBR=terelius@webrtc.org

Bug: webrtc:10336
Change-Id: I8cd27ef9ee044bf7b7e7c1bd1a53c1dae2d95006
Reviewed-on: https://webrtc-review.googlesource.com/c/123886
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26827}
diff --git a/test/rtcp_packet_parser.cc b/test/rtcp_packet_parser.cc
index 5c32fed..c1a8326 100644
--- a/test/rtcp_packet_parser.cc
+++ b/test/rtcp_packet_parser.cc
@@ -55,7 +55,7 @@
           case rtcp::Pli::kFeedbackMessageType:
             pli_.Parse(header, &sender_ssrc_);
             break;
-          case rtcp::Remb::kFeedbackMessageType:
+          case rtcp::Psfb::kAfbMessageType:
             remb_.Parse(header, &sender_ssrc_);
             break;
           default: