Trigger transition in ATMS#resizeTask

This CL changes ATMS#resizeTask to trigger a transition if ShellTransition is enabled.
Also, this CL drops the returning value of the method as no one is using it now.

Bug: 263185856
Bug: 262631137
Test: adb shell am task resize $TASK_ID $x $y $width $height
Test: atest CrossAppDragAndDropTests#testDisallowGlobal
Test: atest CrossAppDragAndDropTests#testOnReceiveContentListener_EditText_GrantRead
Change-Id: I5b32166ceff00dadf7872e8f04564ebfaf8e9a98