Ensure that test BCC are unique per call am: 3c44456c54 am: 07ebfa41fb am: a0d2126c27

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/keymaster/+/15192383

Change-Id: I80ca7b46a9866afedd3c2b066adaeb19f9b2e4cd