Change align_corners to True in position encoding interpolation

[infinity1096]

In current implementation, we have align_corners=False, which according to this post this will led position encoding at the edge be value padded(have the same value as the endpoint of source values, the original PE) and behave differently compared to patches at the center.

We therefore suggest changing to align_corners=True to avoid the difference between PE at the edge v.s. others.

image credit: Lucas Beyer