[Bouncer] Hide status icons in bouncer.

In large screen devices, when we open the shade from Lockscreen and
close it, the bouncer will permanently show the status bar. This is
because we are setting an explicit alpha in split shade mode in
LockscreenShadeKeyguardTransitionController; however we do not reset
this when the shade is dismissed.

Bug: 231460495
Test: Manual on large screen device
Change-Id: I2073f52475b3d716bacf01880be1f59e16873500