Fix issue when starting FLAG_DISMISS_KEYGUARD while occluded

Since KS.dismiss comes in before KG.setOccluded, we didn't defer
Keyguard going away until the shade was closed, which lead to
an ugly switch to the normal shade during the dismissal animation.

Test: Start FLAG_DISMISS_KEYGUARD while occluded to show bouncer,
make sure unlock animation is clean.

Test: Open settings from shade while Keyguard is occluded, make
sure animation is clean.

Change-Id: I31bdeb8077570ef2c50759321178f03601f1fa0d