Adding tests for temporary and renewable trust

Adding unit tests for granting and revoking temporary and renewable
trust. These unit tests should cover basic cases, and that the phone
should be locked/unlocked when expected. Discovered a bug: revoking
trust now also downgrades from trustable and will no longer listen for a
trustable downgrade. Also modified assertLocked and assertUnlocked in an
attempt to reduce flakiness.

Test: atest TrustTests --iterations
Bug: 221155933
Change-Id: I4e0e213427111dbe25a76ff67b6f36e57e295793