Handle KeyguardService#setKeyguardEnabled.

This fixes issues with Security: None, as well as CTS tests (and, I suppose, real apps?) that disable keyguard programmatically.

Test: atest SystemUITests
Test: atest KeyguardTests
Flag: com.android.systemui.keyguard_wm_state_refactor
Bug: 278086361
Change-Id: Id35a4f2f86e52889b4246fadc03b2b3b67476222
13 files changed