Update layout position in SplitLayout (hide IME) without imeLayeringTarget

In case of having an app that set STATE_ALWAYS_HIDDEN, a hide IME call is triggered by losing window focus, e.g. when locking the screen. This also resets the imeLayeringTarget and therefore SplitLayout will ignore all updates from DisplayImeController. After unlocking the screen, the IME was hidden, was the window positions not updated (blank space at the bottom).

This CL enables SplitLayout to take the changed into account (in case of a hide animation), also if there is no imeFocus.

Test: manual: open any app (top) and Chrome (lower window), focus Chrome search bar, lock screen, unlock (without having screen lock set)
Bug: 379792779
Flag: android.view.inputmethod.refactor_insets_controller
Change-Id: Iec0efe101410938bdeb053d4e86dcc325ad43778