Add tests for super_key.rs

The new tests are focused on unlocking, resetting and removing a user.
The tests verify that keys are deleted when necessary and that the user
state transitions properly.

Bug: 280502317
Test: atest keystore2_test on cuttlefish
Change-Id: Idae5d99fb289045bb277ba6c93ab62cfd9aed6fb
3 files changed