Create a shell API to remove desktop

Create a shell API to remove desktop given a displayId. Later on this
can be evolved into using the desktopId instead.

Test: atest DesktopTasksControllerTest
Test: atest DesktopModeTaskRepositoryTest
Bug: 370757235
Flag: com.android.window.flags.enable_desktop_windowing_back_navigation

Change-Id: Id8b1a52d86be395d75db716a9e5d959f92dfdc04
6 files changed