Ignore keyguard transitions FROM an invalid state.

Transitions should only be started FROM the state we most recently started a transition TO. Previously we allowed transitions from the most recently FINISHED state, but this was never the design intent of the keyguard transition graph.

For example, once we've started GONE -> AOD the next transition MUST be AOD -> *. Previously transitions from GONE -> * were also allowed until the transition to AOD FINISHED.

This fixes some issues with temporary legacy code shims that interact with the KeyguardTransitionInteractor, such as https://source.corp.google.com/h/googleplex-android/platform/superproject/main/+/main:frameworks/base/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/FromGoneTransitionInteractor.kt;l=75.

This should have no effect on refactored code. If this causes regressions in refactored code, we should fix those transitions.

Fixes: 325481408
Test: atest SystemUITests
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint TEAMFOOD
Change-Id: Ia239ec9bd4f9d16b23f7a6c53804873fa1c84c81