Enable corner resizing for tiled apps.

This CL enables edge resizing for tiled apps, fixes a bug that prevented
the edge resizing hit boxes from being updated after tiling due to
incomplete equals operator, and fixes the bounds for the tiling divider.

Flag: com.android.window.flags.enable_tile_resizing

Test: on device testing, hit boxes for divider's logic are private to
input handling logic.

Bug: 379663917
Change-Id: Iec1133675eb4271326e540efaf55798471aeed03