Avoid additional focus change when entering PiP from fullscreen

When entering PiP, the task will also be moved to top (from
onRootTaskWindowingModeChanged), and because the activity is
still fullscreen mode during animation, it will be detected as
focusable, that may cause additional focus change.

Also set defer-visibility-update if it is not called from a WCT,
which can reduce additional ensureActivitiesVisible
and resumeFocusedTasksTopActivities when setting the windowing
mode of task (Task#setWindowingModeInSurfaceTransaction). That
also avoid visibility and other states from being updated too
early before a series of PiP operations are done.

E.g.
 moveActivityToPinnedRootTask
   task.setWindowingMode(WINDOWING_MODE_PINNED)
     > ensureActivitiesVisible (can be omitted)
     > resumeFocusedTasksTopActivities (can be omitted)
   task.setBounds(bounds)
   task...
   ensureActivitiesVisible
   resumeFocusedTasksTopActivities

Note that if isPip2ExperimentEnabled() is true, it means that
moveActivityToPinnedRootTask is called from a WCT, and the WCT
should already use setDeferRootVisibilityUpdate. So the logic
of localVisibilityDeferred is the same as !isPip2ExperimentEnabled().

Bug: 307214895
Test: Swipe an immersive auto pip activity to home.
      The bar won't be flickering by changing focus from
      home->pip->home.
Change-Id: I3cb601c4f4c63e2b22e0413764d2eef53387232d