MessageDialog: Fit actions after updating window size, not before
MessageDialog: Fit actions after updating window size, not before

Also, always call #updateWindowSize, because we don't re-fit actions
on window resize (T75783).

Bug: T75376
Change-Id: Icf9e3d0f56c4c3302bb83bfaa3707073bda2381c

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui