SysUITestModule utilities

Introduce a convenience interface SysUITestComponent<UnderTest>, that
can be extended by TestComponents that include SysUITestModule.
Extending this interface gives you a convenient runTest {..} method that
gives the passed lambda access to all of the fields declared on the
component, as well as common TestScope methods.

Flag: NA
Test: atest SystemUITests
Change-Id: Ife5d4d8942a11df8c6aea233f0150a53be1d2368