Allow ActionBarShadowController to attach to Views.

Instead of only allowing ActionbarShadowController to attach to
RecyclerViews, we allow it to attach to any View, as we can listen to
scroll events on them.

Test: See correct behavior when scrolling app info.
Test: atest ActionBarShadowControllerTest
Change-Id: I286a83599bd60ca0a592ee49198b284c5561ec58