Item touch interactions helper class

Notice: TBR, APIs may change

This CL adds a component that can attach to any RecyclerView
and add support for Drag & Drop and Swiping.

It assumes some defaults based on the scroll orientation of
the LayoutManager but can also be extended to customize behavior.

Bug: 18889496
Change-Id: I7aede2084efa599552e053596661fa58b2685d10
24 files changed