Use State.value instead of sample()

Replace some early uses of sample(), which were used to access
state. There is no need for coroutines to flow these values,
and it may cause some race conditions if coroutine execution
is delayed. Just check the current value of the StateFlow.

Fixes: 356696593
Test: atest SystemUiRoboTests:com.android.systemui.keyguard.domain.interactor
Flag: EXEMPT bugfix
Change-Id: I62e8db5a066f888b0402beb91c5044d081b1acab