[PiP on Desktop] Disable swipe up PiP if task is freeform

Bug: 416766306
Test: atest WMShellUnitTests:com.android.wm.shell.pip2.phone
Test: Manual - swipe up after tiling YT with video playing in Desktop,
verify PiP is not entered and there is no crash
Flag: com.android.window.flags.enable_desktop_windowing_pip

Change-Id: I66d883059ee03a39868ba81b3c143baf2bf51b4e