Fix TouchExcludeRegion should ignore the invisible windows

The TouchExcludeRegion could tell the freeform Task if the pointer
event could be excluded or process to resize/move Task. We should
only care about the visible excluded windows or some fullscreen
window like NotificationShade could break the region.

- Ignore the invisible excluded windows.
- Restore pointer icon if in excluded region.
- Add TYPE_VOLUME_OVERLAY to the excluded list.

Bug: 152248369
Test: In default display, enable freeform, enter freeform via recent
      apps, resize window.
Change-Id: I298ddcd984b172161e37fad4d288cee15a0e728c