Avoid consecutive onVisibilityChanged calls

Calling directly onVisibilityChanged(...) from
WallpaperService#updateSurface bypasses the check that the visibility
actually changed. Instead we use doVisibilityChanged(...), which is a
wrapper to onVisibilityChanged that checks that the visibility actually
changed.

This prevents a bug that triggers two consecutive calls to
onVisibilitychanged(false). One of the call comes from engine.attach ->
updateSurface, the other one from picker -> resizePreview ->
updateSurface.

Flag: ACONFIG com.android.window.flags.no_consecutive_visibility_events DEVELOPMENT
Bug: 285631818
Bug: 313527496 (to be verified)
Test: manually check onVisibilityChanged(false) logs
Test: treehugger
Change-Id: I4fc189cdb9d4b4de36d88fe27ad651ddf0b40449