Add av1 to lower range IDs.

Higher range of IDs for peer connection has been exhausted.
Adding AV1 to lower range as it was blocking enabling
libaom by default.

This is blocking crrev.com/c/2617229

Bug: chromium:1095763
Change-Id: If5135122954d00cc03afc563071aec99f145140b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/201523
Commit-Queue: Jerome Jiang <jianj@google.com>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32967}
diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index 84b61db..758e495 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -167,7 +167,8 @@
   for (const webrtc::SdpVideoFormat& format : supported_formats) {
     VideoCodec codec(format);
     bool isCodecValidForLowerRange =
-        absl::EqualsIgnoreCase(codec.name, kFlexfecCodecName);
+        absl::EqualsIgnoreCase(codec.name, kFlexfecCodecName) ||
+        absl::EqualsIgnoreCase(codec.name, kAv1CodecName);
     if (!isCodecValidForLowerRange) {
       codec.id = payload_type_upper++;
     } else {