Do not set a disallowedAreaForEndBounds for caption window decors

The disallowedAreaForEndBounds is meant to be used when another
component will handle a drag move end in that region (such as a
transition to fullscreen in desktop mode) and the positioner does
not need to finalize the bounds change with a WCT.
Caption window decorations does not have another component handling
the task moves within the status bar region, so the disallowed
area should not be set so that the positioner can finalize the bounds
correctly.

Bug: 281129969
Test: drag-move a task in freeform on a pixel into the status bar
area, release and confirm the task surface is not stuck behind the
status bar.

Change-Id: Ic7aa895c7b3d71619a8eb03f432e15f37d469f27