Add support for no-background items

In RecyclerItemAdapter, if the root view of a layout has the tag
"noBackground", the background will not be added to the item. In that
case the layout itself is responsible for any touch feedback, for
example by setting part of its background to selectableItemBackground.

Test: ./gradlew connectedAndroidTest test
Bug: 36388000
Change-Id: I0735e47b2dc599ad49741be602f7de6ebfce02a0