Initial use of Kosmos in SceneTestUtils and associated tests.

This shows how we can begin to bring in Kosmos incrementally, but does not take
any particular class to the final "this is fixed" state.

Bug: 303103876
Test: ./gradlew :SystemUILib:testAospDebugUnitTest
Flag: NONE
Change-Id: If65b86ae7a02e23589a81acb4cdd0d28428201f2