Properly fixing expansion state in lockscreen to shade transition

This is follow up to ag/18436783 which was just a quick fix, even though it also introduced important scrim-related fix.
This change updates QS expansion along lockscreen to shade transition in split shade.
That uncovered some inconsistent behaviour in split shade like calculating top notifications padding or max panel height which are also fixed here.

Bug: 228198572
Test: expand shade from split lockscreen and see most bottom tiles functioning properly (requires 9 tiles visible in split shade)
Change-Id: Ia68d9ec80eeeff56d2db7538449d0162ce6e690f