[PiP on Desktop] Check App Ops before minimizing to PiP.

Recall: http://recall/clips/b3121879-70fc-4d51-a326-57a5480298d9

When swiping up to enter PiP, AbsSwipeUpHandler on the Launcher side
checks AppOps to see if the app is allowed to enter PiP. This CL adds
this check for Desktop PiP as well (when minimizing to PiP) so it
respects what is set in Settings.

Bug: 370061716
Test: atest DesktopTasksControllerTest
Flag: com.android.window.flags.enable_desktop_windowing_pip
Change-Id: I1451ac8d9723839283b221113a83720212fa15f9