On reset, show keyguard if not already shown

This is to address an inconsistent state when the keyguard service
thinks the keyguard should be visible but the keyguard view does not.

Bug: 155706342
Bug: 156440963
Test: manual, atest ActivityLifecycleKeyguardTests
Change-Id: I566802e5d71a4ce387c9f31951ffa33be664c7b2