Delete grants to a user ID when it is removed.

Currently, if there is a grant to user ID 1 for app ID A and then user
ID 1 is removed and a new user is created with user ID 1, that new user
will inherit the grant for app ID A, which would give it access to a
key it shouldn't have access to.

Bug: 372415590
Test: atest keystore2_test
Change-Id: Id19bc31968df9c54ac5fb100f3bf471441eb989c
2 files changed