Fix shape is sometimes too small on lockscreen

Avoid sending wrong bounds from homescreen to wallpaper by filtering the FINISHED transitionStep to LOCKSCREEN, and filtering out the FINISHED transitionStep from LOCKSCREEN

Test: manual test that no bounds is sent to wallpaper when unlocking
Bug: 396667623
Flag: com.android.systemui.shared.extended_wallpaper_effects

Change-Id: Ied576062ebdfb44ba0814b26c8db4505647055d2