Offset animation leash to the relative position

When the snapshot surface is created, it should remain at its
original position.

When the animation starts, change animation bounds should be at the
start bounds relative position.

Bug: 196173550
Test: atest WmTests:RemoteAnimationControllerTest
Test: Test with demo app full -> split with RTL enabled.
Change-Id: I3cb44e1f222870f51105bfaa98fc4febaafec03b