Added an onDeviceUnlockLockout callback to TrustAgentService.

Test: Manually tested onDeviceUnlockLockout being called with an actual
TestAgentService implementation.

Notes:
- Active Trust Agents are no longer killed/unbinded from when a temporary
  device lockout occurs. Instead, the onDeviceUnlockLockout callback of
  the agent is called.

Change-Id: Ifa0984d1d7e5153568334d736e9ebd5a00ef1297
Bug: 34198873