TODOs: UI tests for TodoListActivity

Some of the code from MainActivityTest was extracted into TestUtil.

These tests cover the following interactions:
- Swipe left (to delete)
- Swipe right (to mark as done)
- Tap (to edit or delete)
- FAB (to add)
- Menu (to show done)
- Menu (to edit or delete the ListSpec)

The same strategy was used as the previous tests. The UI interaction
to Persistence was tested separately from the Listener call to UI
response.

Change-Id: I9b55edd6d34a0b78d23e961d7c85da91ff66865e
5 files changed