Add more customization options to the PagedListView's divider.

Changes include:
- Allow divider's start/end position to be configured based on a view.
- Allow a starting offset to the divider to be set

Also, clean up how the divider handles the case where no dividing lines
should be drawn. Now, just don't set an ItemDecorator in that case.

Test: built all apps and verified nothing has changed.
Bug: 63524971
Change-Id: I662e7c7120d0ed30afcb01268b7a7ac3c725075d
2 files changed