D15611: [KCollapsibleGroupBox] Respect style's widget animation duration

[Elvis Angelaccio]

elvisangelaccio accepted this revision.

REPOSITORY
  R236 KWidgetsAddons

REVISION DETAIL
  https://phabricator.kde.org/D15611

To: cfeck, #frameworks, ngraham, elvisangelaccio
Cc: broulik, ngraham, kde-frameworks-devel, michaelh, bruns