Update progress bar and seek bar backgrounds, fix seek bar thumb

Ensures LayerDrawable copies out the correct layer properties during
"tileification". This really needs to be deprecated or replaced in a
future CL, though, because it is potentially lossy (e.g. for
RippleDrawable, which is an instanceof LayerDrawable).

Bug: 19448441
Change-Id: I483e9c34fd781e280c13eb5951f96bc71a252819
14 files changed