Update windowing mode with acitivity option in freeform mode

Currently relaunching with freeform activity option is a no-op for
a fullscreen app in feeform mode, because even if freeform is
specified in activity option, it's resolved as W_M_UNDEFINED in
TaskLPM because the windowing mode of the display is freeform.

However, in this specific case, we need to make sure to update the
windowing mode of the fullscreen task.

Bug: 321113764
Test: WindowMetricsActivityTests#testMetricsMatchesLayoutOnFreeformActivity
Change-Id: Ie17526ed47942356b8e60ba9eede0c3df689a745