Invert dependency between NEM and RowBinder

NotificationEntryManager needs a NotificationRowBinder to inflate views
and bind them. Previously, it did this by calling Dependency.get(), but
this resulted in a circular dependency.

We can't fully break the circularity, but we can make it more explicit.
This CL inverts the dependency -- now the NEM needs someone else to give
it a row binder before it can function properly. Among other things,
this makes testing easier.

This CL allows us to isolate the interface between the NEM and NRB; in
later CLs we can make explicit the async inflation callback between the
NEM and the NRB and finally rewrite most of the NEM tests.

Test: atest
Change-Id: Ibb6ca4416456021a3c0a3679d1d74248fca18af6