Remove FAB hiding and showing

In AOSP the fab hides and shows at certain times based
on what the user is doing (typing in search field or
scrolling through results). There's a bug where sometimes
the FAB does not come back.

Just show the FAB all the time as our UI changes allow
the fab to be visible when the keyboard is.

Ticket: CD-442
Change-Id: I1939e213deaad0ea582e1dbe4b495fb9b710447e