QmlProfiler: Increase flame graph view context menu test timeout

Apparently macOS will block the event loop until a real mouse click
happens if you open and close context menus in quick succession. When
it does that, the timer won't hit anymore and the mouse event to trigger
the next test step won't be generated.

Change-Id: Ie0c05d8a5a2020fe46381358133cd7cdbbf42299
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/qmlprofiler/tests/flamegraphview_test.cpp

@@ -122,7 +122,7 @@ void FlameGraphViewTest::testContextMenu()
     QSignalSpy spy(&view, SIGNAL(showFullRange()));
 
     QTimer timer;
-    timer.setInterval(50);
+    timer.setInterval(500);
     int menuClicks = 0;
 
     connect(&timer, &QTimer::timeout, this, [&]() {