Add missing number 3 to permitted RID characters.

Bug: chromium:1049995
Change-Id: Iac13d70fb24f9dc5f36937d625ce33bd7152b092
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144079
Auto-Submit: Harald Alvestrand <hta@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758177}

third_party/blink/renderer/modules/peerconnection/rtc_peer_connection.cc

@@ -2288,7 +2288,7 @@ RTCRtpTransceiver* RTCPeerConnection::addTransceiver(
     }
     // Allowed characters: a-z 0-9 _ and -
     if (encoding.rid.find_first_not_of("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLM"
-                                       "NOPQRSTUVWXYZ012456789-_") !=
+                                       "NOPQRSTUVWXYZ0123456789-_") !=
         std::string::npos) {
       exception_state.ThrowTypeError("Illegal character in rid");
       return nullptr;