Implement autofill and activity launch

Upon clicking on an action, we need to perform either remote-autofill,
or execute the intent provided by SmartSpace.

Test: atest AmbientCueRepositoryTest
Test: atest AmbientCueInteractorTest
Bug: 403422950
Flag: com.android.systemui.enable_underlay
Change-Id: I0460f2efc344bca541e2c971ffecabc7e538a42b