Fixed cutout not being updated for non hwc layer

Call onDisplayChanged for non-hwc cutout view to update cutout.

Bug: 221242189
Test: manual:
      1. select double cutout emulation in settings
      2. reboot device and check the cutout
Test: atest ScreenDecorationsTest
Change-Id: I7272249a5a708d5c359d02f3330eb038c7747c78