Handle DISPLAY_DECORATION

I90543850d57323be485a0fa8562f4e965aed28ab in hardware/interfaces
introduces the new Composition type, DISPLAY_DECORATION. Handle this
case when looking at Composition.

Bug: 193170859
Test: TODO
Change-Id: Ic5d5881dbbbaa348bf5ba39c5f8a4fca7b7170b4
4 files changed