[SB] Only hide the status bar if the shade is at least 40% showing.

If you have a HUN then start a touch event on it to swipe it away or
swipe open the shade, then the shade starts at ~23% expanded, which was
enough for HomeStatusBarViewModel to decide the shade is "expanded
enough" so we should hide the status bar. This CL increases that
"expanded enough" threshold to 40% so that the status bar doesn't
immediately disappear when interacting with a HUN.

Fixes: 412820391
Bug: 394257529
Flag: com.android.systemui.status_bar_root_modernization
Test: atest HomeStatusBarViewModelImplTest
Test: Trigger normal HUN then drag up to dismiss -> verify status bar
doesn't hide
Test: Trigger normal HUN then drag down to open shade -> verify status
bar doesn't hide
Test: Trigger chip, tap chip to show HUN, then drag up to dismiss ->
verify status bar doesn't hide
Test: Trigger chip, tap chip to show HUN, then drag down to open shade
-> verify status bar doesn't hide

Change-Id: I5b94620b5b4c35d2ac3c0bbe590bd01fb1c91477