Changes:
- Update ambient-viewer unittest
- Add factory methods to improve testability
- Adds unittest for watch-holder
- Add unit tests for ambient viewer
- Add unittests for Watch class
Change-Id: I6127161e766c2e7dde05c9dff6309cdadb4f1b34 Signed-off-by: Junghoon Park <jh9216.park@samsung.com>