- Add a controller to manage add/remove onScrollChangedListener to
recyclerviews.
- When recyclerview on each screen is scrolled to top, set actionbar
elevation to 0, otherwise set it to non-zero.
- When screen is moved to background, detach the listener.
- Use the controller in entity header.
Change-Id: Iecf194d885098c98c392810f62893ae9189f3936
Fix: 37670670
Test: make RunSettingsRoboTests