Support transient-launch recents with freeform

There were some narrow checks which would reject transient
launch of recents when there are freeform windows and would
also cause some premature visibility changes.

This resolves that by:
- allowing recents shortcut even if the recents is already visible
  as long as it isn't already on top.
- Allowing transient-launch to transient-hide freeform tasks.

Bug: 302023399
Test: open app in desktop, swipe to overview.
Change-Id: If2e1ef3327bef99e65f713c975eb055e8c832984