Support long edge cutouts for ScreenDecorations

1. Add two more overlay windows for long edge sides and now there could
be maximum 4 windows at the same time.

2. To optimize the number of window used, rounded corners should be
shown on left and right overlay windows if there is only long edge
cutout(s).

3. Remove the window when there is no cutout on its edge.

4. Enable the CutoutSpace on landscape in PhoneStatusBarView so that
icons on status bar won't be covered by the long edge cutout.

Bug: 146884519
Test: atest ScreenDecorationsTest
Change-Id: I97f042e96ea06285dc5f0b517dec1c7fb91b5b12