Refactor listener to centralize value logic.

Refactor listener group to centralize management of reporting the last
value. Track the last reported value in the Listener group.

Flag: android.view.flags.root_view_changed_listener
Bug: 394397033
Test: atest CtsViewTestCases:WindowInspectorTest
Change-Id: Idf7988428955e2d9bd1f987327905cce89f19798