[flexiglass] SysUiState correction during SUW.

During SUW (setup wizard), before the device is "provisioned", the
SysUiState published by System UI wasn't right.

This CL addresses that by taking the visibility of System UI into
account when publishing SysUiState flags. The visibility already takes
device provisioning state into account.

The command that can show the current SysUiState flags is:
$ adb shell dumpsys activity service com.android.systemui/.SystemUIService | grep SysUiState -A 10

Bug: 396690884
Test: unit tested updated
Test: running the command above during SUW yields the same output with flexiglass
on or off
Test: passed SUW, manually smoke tested all scenes with flexiglass on
Flag: com.android.systemui.scene_container

Change-Id: If349f5885ee576baeaa6496b929f61347cbcd249