Ensure that test BCC are unique per call am: 3c44456c54 am: a9cd1e7a6e am: da1a9b7bff

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

Change-Id: I03f6f629e15b3cb28f0d705a7bcafd1062308407