Make WebRTC Connections more robust

It turns out that the iceConnectionState on the connectionStateChange
event is about a particular ICE Candidate pair, which may not be the
selected and in use candidate pair. However checking the
iceConnectionState on the WebRTCPeer object itself yields the state of
the “selected” and in use candidate pair.

Change-Id: I7d14041300ce82a02fd1bd04b9a940f26216d802

appinventor/blocklyeditor/src/replmgr.js

@@ -445,7 +445,7 @@ Blockly.ReplMgr.putYail = (function() {
             webrtcpeer = new RTCPeerConnection(top.ReplState.iceservers);
             webrtcpeer.oniceconnectionstatechange = function(evt) {
                 console.log("oniceconnectionstatechange: evt.type = " + evt.type + " connection state = " + this.iceConnectionState);
-                connectionstate = this.iceConnectionState;
+                connectionstate = webrtcpeer.iceConnectionState;
                 if (connectionstate == "disconnected" ||
                     connectionstate == "failed") {
                     webrtcerror(true, Blockly.Msg.REPL_WEBRTC_CONNECTION_ERROR + "\n" + "state = " + connectionstate);