Delete expired CE APEX snapshots when user unlocks.

This adds a call to the new destroyCeSnapshotsNotSpecified method
of ApexService, to delete all expired CE snapshots when a user
unlocks.

See ag/10552991 for the apexd side of this change.

Cherry-pick and manual merge of ag/10564717 (from rvc-dev) to avoid
conflict.

Bug: 147806409
Test: Manual - install APEX with rollback enabled, expire the rollback,
check that snapshot is deleted.
Change-Id: Icf31d1dd67449edc22d530798a0d67d329e30b62