Delete member VideoReceiveStream::Config::Rtp::ulpfec.

Replaced with scalars ulpfec_payload_type and red_payload_type.

In particular, ulpfec.red_rtx_payload_type, which duplicated info in
rtx_associated_payload_types, is deleted. This is a followup to cl
https://codereview.webrtc.org/3012963002.

BUG=webrtc:7135

Review-Url: https://codereview.webrtc.org/3019453002
Cr-Commit-Position: refs/heads/master@{#19965}
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index 0eeae21..faf47c7 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -520,9 +520,9 @@
       send_config->rtp.extensions.push_back(RtpExtension(
           RtpExtension::kAbsSendTimeUri, test::kAbsSendTimeExtensionId));
     }
-    (*receive_configs)[0].rtp.ulpfec.red_payload_type =
+    (*receive_configs)[0].rtp.red_payload_type =
         send_config->rtp.ulpfec.red_payload_type;
-    (*receive_configs)[0].rtp.ulpfec.ulpfec_payload_type =
+    (*receive_configs)[0].rtp.ulpfec_payload_type =
         send_config->rtp.ulpfec.ulpfec_payload_type;
   }