Rename fold-unfold animation overlay and surface-container

Rename fold-unfold animation overlay and surface-container for better visibility in winscope trace. Currently the container is named as 'LayoutParams' which is incorrect.
This will also help in testing, to tell fold and unfold overlay apart from each other.

Test: atest FoldAnimationVisibleOnLauncher
Bug: 328219437
Flag: com.android.internal.foldables.flags.fold_lock_setting_enabled
Change-Id: I3caafc29496317b51dc478feaf2594b4cc272629