Restrict change mode to apply transition background

Previously it only checks the transition type. It will incorrectly
add the background color for a CHANGE mode window.

An example:
 CLOSE type {
   CLOSE mode: translucent
   CHANGE mode: opaque
 }

Bug: 281010752
Test: Launch a translucent activity and it calls
      Activity#finishAndRemoveTask(). A fullscreen background
      color should not show.
Change-Id: Iff51289467c448b422f4011e14b9fd61de881b45
2 files changed