Use display of activity to get rotation for recents

The rotation of WindowConfiguration in Configuration is non-public
field. There is no guarantee that the information will be updated.
E.g. a 180 degree rotation change won't make difference to the
public configurations, so the Resources will keep the old one.

The display rotation of activity is accurate to use for its content
because even the activity is transformed to different rotation than
the physical display, there is FixedRotationAdjustments to adjust
the information which will be consistent as how the activity is
laid out.

Bug: 159877752
Test: 1. Enable auto rotation.
      2. Launch some portrait activities.
      3. Put device in reverse portrait (upside down).
      4. Launch a landscape activity.
      5. Swipe to another activity with full-sensor orientation.
      6. Return to home and enter recents to check the task views
         of step 2 don't show upside down.

Change-Id: I5e16e71d43b8892a394c06de9e76fb3d4ad55919