Call to notify that foreground MIDlet is changing and give the
display controller a chance to preempt the change.
Also the last MIDlet created state will be reset.
If the MIDlet to get the foreground is paused, then activate it.
MIDletProxy oldForeground = midletProxyList.getForegroundMIDlet();
MIDletProxy newForeground = super.foregroundMidletChanging(midlet);