Use allow list for quick settings tiles for headless system user

The headless system user should only see specific quick settings
tiles. The allow list is specified in the SysUI config file. If
the allow list is empty, then all tiles will be allowed.

Bug: 405225580
Test: atest HsuTilesRepositoryTest CurrentTilesInteractorImplTest
Flag: com.android.systemui.hsu_qs_changes
Change-Id: I11601c8503690378750b8b3c0004f3ee150bd54b