[2/n] Cascade windows in desktop windowing

Windows should be opened in the order of:
1. Center
2. Bottom right
3. Top left
4. Bottom left
5. Top right
and repeat.

Flag: com.android.window.flags.enable_cascading_windows
Test: atest DesktopTasksControllerTest
Bug: 280496681
Change-Id: Id7cd63a421f812ddaf47edec5c5707b6c2caa106