Move LockSettingsInternal into services

Now that LockPatternUtils no longer depends on LockSettingsInternal,
move LockSettingsInternal and the callback classes associated with it
(EscrowTokenStateChangeCallback, LockSettingsStateListener, and
RebootEscrowListener) into the services jar where they belong.

Bug: 408077877
Test: atest Frameworks{,Mocking}ServicesTests:com.android.server.{devicepolicy,locksettings,recoverysystem,trust}
Test: atest Frameworks{,Mocking}CoreTests:com.android.internal.widget
Flag: EXEMPT refactor
Change-Id: Iba28fb358e790cdf293911d7fc85f8b06ac16873