Create unit tests for datatypes

Also, introduce a base class for all common datatypes to avoid missing
equals/toString implementations

The tests are not complex but should avoid memory issues because of missing caching, incorrect string formatting and other functionality

Bug: 262241371
Test: atest FlickerLibTest
Change-Id: Ifdec189d40c73708571f7f773b607d73bd2d0d9b
44 files changed