example, touchinteraction: use forceActiveFocus to gain focus

Use forceActiveFocus to gain focus when the user clicks on
a note. Just setting focus on an item is not enough to gain
keyboard focus.

Change-Id: Ia4a68a17df0df4b321cc6edb646b39c36167e982
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>
Reviewed-by: Caroline Chao <caroline.chao@theqtcompany.com>