Don't create gap between last task and clear all button

- If a task is too close to ClearAllButton when being snapped to, change the snap position to barely not seeing ClearAllButton
- When snapping to the above tasks from quick switch, apply a horizontal grid translation to smoothly snap into  position
- Apply the above grid translation to TaskViewSimulator as well

Bug: 192254835
Test: manual
Change-Id: I32d562a1726f7c8b41ac10c7deece890df7e1304