Hide tooltip when PrivateActionToolButton is pressed
Summary: The tooltip used to remain even as the button was pressed, now it doesn't/shouldn't.
Test Plan: Look at a bunch of instances of this and make sure the tooltip hides on button press.
Reviewed By: Kirigami, ngraham
Subscribers: ngraham, mart, plasma-devel
Differential Revision: https://phabricator.kde.org/D21877