Fix focus handling in android manifest editor

If focus gets set on the editor widget, either the current focus widget
of the current page (gui/text) should receive application focus, or the
page itself (where the gui page should defer that to its first input
widget).

Change-Id: I8a35c2e9ca06fe694069b594788f7f40307abbda
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>

src/plugins/android/androidmanifesteditorwidget.h

@@ -112,6 +112,7 @@ signals:
 
 protected:
     bool eventFilter(QObject *obj, QEvent *event);
+    void focusInEvent(QFocusEvent *event);
 
 private:
     void setLDPIIcon();