Fix KeyguardIndicationAreaViewModelTest that fails when flexi is enabled

KeyguardIndicationAreaViewModel uses communalSceneInteractor#isCommunalVisible which relies on SceneInteractor to determine the current scene.

Bug: 409851925
Test: unit test passes with flexi enabled
Flag: com.android.systemui.scene_container
Change-Id: I335be5f994ba93dc4516f89736f55dfd751e84b1