Adjust animation end callback for SystemUI

This avoids the potential heavy operation in onAnimationEnd
from being included in animation frame, so the last frame
jank might reduce.

Bug: 300035126
Flag: com.android.window.flags.system_ui_post_animation_end
Test: presubmit
Change-Id: I40a59e594b36450c8fa5406f29d90eb3668b4910