Prevent notif flicker during entirety of swipe to unlock

The current shade relies of status bar state, and so we still
need to check this to confirm that the user has completely
unlocked their device.

Also, remove redundant transition and update shadeExpansion to
be state flow (which matches the rest of the shade flows).

Test: atest SharedNotificationViewModelTest
Fixes: 329236043
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
TEAMFOOD

Change-Id: I0af12eed5046b9238f66646f9752f48f18aae560