Update dependency descriptor rtp header extension uri

to match one in av1 rtp spec examples:
https://aomediacodec.github.io/av1-rtp-spec/#73-example

Bug: webrtc:10342
Change-Id: Ib108b90f6103d050d61d40fc36ad1c2a358f3f21
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168641
Reviewed-by: Markus Handell <handellm@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30531}
diff --git a/modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.h b/modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.h
index d6e0804..b99230c 100644
--- a/modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.h
+++ b/modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.h
@@ -26,8 +26,8 @@
   static constexpr RTPExtensionType kId = kRtpExtensionGenericFrameDescriptor02;
   // TODO(bugs.webrtc.org/10342): Use uri from the spec when there is one.
   static constexpr char kUri[] =
-      "http://www.webrtc.org/experiments/rtp-hdrext/"
-      "generic-frame-descriptor-02";
+      "https://aomediacodec.github.io/av1-rtp-spec/"
+      "#dependency-descriptor-rtp-header-extension";
 
   static bool Parse(rtc::ArrayView<const uint8_t> data,
                     const FrameDependencyStructure* structure,