Fixes a list equality check and adds a refreshResults() method.

Previously, the lists being compared could point to the same
object (e.g. from a separate class like ZeroStateResultProvider),
thus always being equal. This prevented the RecyclerView from
updating in certain cases.

Also added an option new method to SearchUiManager which can be
used to trigger a refresh.

Bug: 207651359
Test: Manual
Change-Id: I9c7f02fcd9dfb91326eccf1d4eb8692904702ab0