Animate PiP with considering next rotation

- Make sure that fixed rotation state is set in
  PipTransition#startEnterAnimation according to the change info.
- Call setEndFixedRotation if the display rotation will be changed
  by a different task.

Also remove a dead code in handleSwipePipToHomeTransition which
was fixed by commit 19da8aeb.


Bug: 285089607
Test: Case 1: Click notification which starts an activity in
              a different orientation with remote animation
              and make the pausing app enter PiP at the same time.
      Case 2: A task contain 2 activities, its top activity enters
              PiP in a new task from landscape. And the next activity
              in the task is portrait.

Change-Id: Ibcf2bb90a0abd0c100d48aa27f1b7ab93e8d78ec