Set Containments to have focus within the view

Summary:
Now that applets are their own focus scope (which makes sense) we've
also made containments their own focus scope.

We therefore need to also say the containment FocusScope has the focus
within the view.

BUG: 381124

Test Plan:
Renamed something in folderview
Used cursor nav

Reviewers: #plasma

Subscribers: plasma-devel, #frameworks

Tags: #plasma, #frameworks

Differential Revision: https://phabricator.kde.org/D6192

src/plasmaquick/containmentview.cpp

@@ -135,6 +135,7 @@ void ContainmentViewPrivate::setContainment(Plasma::Containment *cont)
     if (graphicObject) {
 //         qDebug() << "using as graphic containment" << graphicObject << containment.data();
 
+        graphicObject->setFocus(true);
         //by resizing before adding, it will avoid some resizes in most cases
         graphicObject->setProperty("width", q->width());
         graphicObject->setProperty("height", q->height());