Fix SnapResizeAppWindowLeftWithDrag Assertions

Tiling made it so that the assertions on the size of the snap resize windows was off, so follow the example of the SnapResizeAppWindowWithButton fix and add a threshold to the assertion

Bug: 377079516
Change-Id: Ib91ab4412872bed092a3bb713b25eac92cfb6926
Test: atest SnapResizeAppWindowLeftWithDrag
Flag: TEST_ONLY