Introducing VibratorHelper Fixture in Kosmos

A FakeVibratorHelper is added as a Fixture in Kosmos for better
testability of haptic features that depend on the VibratorHelper. The
dependency avoids hardware interactions (with any Vibrator) and only
keeps track of a history of vibrations "delivered". The list of
supported haptic primitives is also customizable.

Test: atest SystemUITests:SliderHapticFeedbackProviderTest
Flag: NONE
Bug: TBD

Change-Id: I4c8ac023a2f8a1a086ea114bf3da3fb82ae25dfb