Simple tests for Fragment Views.

Bug 29936579

Adds tests for add, remove, replace, hide, show, attach, and
detach. These are simple tests to show that Fragment Views are
properly added and removed and hidden after execution. It
also verifies some illegal operations (e.g. adding a fragment
that is already added) are disallowed.

Change-Id: Id2e1a37c09c13e0427f1567b3c1d157c3324f295
3 files changed