Add password expiration plumbing

* Set aggregated expiration values with DPM
* Fix min/max logic when aggregating, and fix unit test
* Add expiration tests when checking if policies are active
* Add expire-password to uses-policies set
* Handle password refresh (clear notifications and sec. holds)
* Handle password expiration (warning and/or wipe synced data)
* Unit tests for provider-level methods
* Refactor common security notification logic
* Placeholder notification strings (need final)

Bug: 3197935
Change-Id: Idf1975edd81dd7f55729156dc6b1002b7d09841f
3 files changed