Update Qt sample to work now that we use ES modules in the Glean library

Author: brizental

samples/qt-qml-app/main.qml

@@ -6,7 +6,7 @@ import QtQuick 2.0
 import QtQuick.Controls 2.0
 import QtGraphicalEffects 1.15
 
-import "../../glean/dist/qt.js" as Glean;
+import "../../glean/dist/glean.js" as Glean;
 // These must be imported after Glean because they rely on Glean being in the environment.
 import "./generated/pings.js" as Pings;
 import "./generated/sample.js" as Metrics;
@@ -66,7 +66,7 @@ Rectangle {
 
   Component.onCompleted: {
     // Initialize Glean.
-    Glean.Glean.initialize("qt-qml-app", true, { debug: { logPings: true }});
+    Glean.Glean.default.initialize("qt-qml-app", true, { debug: { logPings: true }});
     Metrics.sample.appStarted.set();
     // !IMPORTANT!
     // If this message is changed the check in bin/qt-js-check **must** be updated.