Make SysUI Classic Feature Flag loading multi-user aware.

This ensure that flags can be loaded properly on HSUM builds.

Bug: 345443431
Test: Launch the flippin app on HSUM and no crashes
Flag: com.android.systemui.classic_flags_multi_user
Change-Id: I05e2246ab5027bc7dcace9663418da883b7fa47b
2 files changed