Fix network_ui.js: getShillDeviceProperties() call for mojo

This is developer debugging UI only, and a subtle use cases that I
only noticed when investigating a bug where a Cellular device property
is not getting set by Shill. (The information is still available in
chrome://system and in feedback reports).

Bug: none
Change-Id: I6435435c0ccf7cfd1608635631c0f6311c30fc34
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815547
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699067}

chrome/browser/resources/chromeos/network_ui/network_ui.js

@@ -388,7 +388,9 @@ const NetworkUI = (function() {
    */
   const handleDeviceDetail = function(state, selectedId, detailCell) {
     if (selectedId == 'shill') {
-      chrome.send('getShillDeviceProperties', [state.type]);
+      chrome.send(
+          'getShillDeviceProperties',
+          [OncMojo.getNetworkTypeString(state.type)]);
     } else {
       showDetail(detailCell, state);
     }