Fix app to folder icon animation.

- Needed to account for the preview bounds (similar to BubbleTextView icon
  bounds)
- Also needed to update the bitmap shift amount so that it is re-centered
- Moved ShiftedBitmapDrawable to its own class in graphics package

Bug: 123900446
Change-Id: Ifa9e3f688e55d017cf86a0285f5cdb1b014f01e6