Exclude screen decoration overlay from transition participants

It doesn't need an animation and its surface layer should not be
changed by transition.

Bug: 288726181
Test: Switch screen size by "Settings > Display > Screen resolution"
      or "Display size and text > Display size".
      Check "adb shell dumpsys SurfaceFlinger | grep -A10 ScreenDecor"
      The parent of ScreenDecor's should be none (root).
      And ScreenDecor doesn't move to "Offscreen Layers".
Change-Id: Ib5262f6d4be3aac4f83a82bd9e93bad7437ef640