Remove flexiglass dependency from repository that is used by existing code

This reduces the flexibility we have in changing flexiglass code.
We will be changing the implementation of DeviceEntryInteractor#isUnlocked to not depend on keyguard going away state from the legacy system.

Bug: 295366149
Test: everything builds and runs.
Flag: NA (this is reverting unflagged code that was added before)

Change-Id: I5c6bbcd8acc61e3c7a8f47c622f0f77883c51aec